Anatomic subsite of primary colorectal cancer and subsequent risk and distribution of second cancers

Associations between pathological features and risk of metachronous colorectal cancer

Survivors of colorectal cancer (CRC) are at risk of developing another primary colorectal cancer - metachronous CRC. Understanding which pathological features of the first tumour are associated with risk of metachronous CRC might help tailor existing surveillance guidelines. Population-based CRC cases were recruited from the United States, Canada and Australia between 1997 and 2012 and followed prospectively until 2022 by the Colon Cancer Family Registry. Metachronous CRC was defined as a new primary CRC diagnosed at least 1 year after the initial CRC. Those with the genetic cancer predisposition Lynch syndrome or MUTYH mutation carriers were excluded. Cox regression models were fitted to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for the associations. Of 6085 CRC cases, 138 (2.3%) were diagnosed with a metachronous CRC over a median follow-up time of 12 years (incidence: 2.0 per 1000 person-years). CRC cases with a synchronous CRC were 3.4-fold more likely to develop a metachronous CRC (adjusted HR: 3.36, 95% CI: 1.89-5.98) than those without a synchronous tumour. CRC cases with MMR-deficient tumours had a 72% increased risk of metachronous CRC (adjusted HR: 1.72, 95% CI: 1.11-2.64) compared to those with MMR-proficient tumours. Compared to cases who had an adenocarcinoma histologic type, those with an undifferentiated histologic type were 77% less likely to develop a metachronous CRC (adjusted HR: 0.23, 95% CI: 0.06-0.94). Existing surveillance guidelines for CRC survivors could be updated to include increased surveillance for those whose first CRC was diagnosed with a synchronous CRC or was MMR-deficient.

Survival trends for left and right sided colon cancer using population-based SEER database: A forty-five-year analysis from 1975 to 2019

BACKGROUND

Survival differences between left-sided colon cancer (LSCC) and right-sided colon cancer (RSCC) has been previously reported with mixed results, with various study periods not accounting for other causes of mortality.

PURPOSE

We sought to assess the trends in colon cancer cause- specific survival (CSS) and overall survival (OS) based on sidedness.

METHOD

Fine-Gray competing risk and Cox models were used to analyze Surveillance, Epidemiology, and End Results (SEER) population-based cohort from 1975 to 2019. Various interval periods were identified based on the timeline of clinical adoption of modern chemotherapy (1975-1989, interval period A; 1990-2004, B; and 2005-2019, C).

RESULTS

Of the 227,637 patients, 50.1% were female and 46.2% were RSCC. RSCC was more common for African Americans (51.5%), older patients (age ≥65; 51.4%), females (50.4%), while LSCC was more common among Whites (53.1%; p < 0.001), younger patients (age 18-49, 64.6%; 50-64, 62.3%; p < 0.001), males (58.1%; p < 0.001). The Median CSS for LSCC and RCC were 19.3 and 16.7 years respectively for interval period A (1975-1989). Median CSS for interval periods B and C were not reached (more than half of the cohort was still living at the end of the follow-up period). Adjusted CSS was superior for LSCC versus RSCC for the most recent interval period C (HR 0.89; 0.86-0.92; p < 0.001). LSCC consistently showed superior OS for all study periods. Stage stratification showed worse CSS for localized and regional LSCC in the earlier study periods, but the risk attenuated over time. However, left sided distant disease had superior CSS per stage for all interval periods. OS was better for LSCC irrespective of stage, with gradual improvement over time.

CONCLUSION

LSCC was associated with superior survival compared to right sided tumors. With the adoption of modern chemotherapy regimens, prognosis between LSCC and RSCC became more divergent in favor of LSCC. Colon cancer clinical trials should strongly consider tumor sidedness as an enrollment factor.

Second primary cancer among 217702 colorectal cancer survivors: An analysis of national German cancer registry data

With improvements in survival after colorectal cancer (CRC), more survivors are at risk of developing a second cancer, particularly in younger populations where CRC incidence is increasing. We estimated the incidence of second primary cancer (SPC) in CRC survivors and its potential risk factors. We identified CRC cases diagnosed between 1990 and 2011 and SPCs until 2013 from nine German cancer registries. Standardized incidence ratios (SIR) and absolute excess risk (AER) per 10 000 person-years were calculated and were stratified by index site: colon cancer (CC) and rectal cancer (RC), age and sex. Cox regression assessed potential SPC risk factors, including primary tumor-related therapy considering death as a competing risk. We included 217 202 primary CRC cases. SPC occurred in 18 751 CRC survivors (8.6%; median age: 69 years). Risk of cancer was significantly higher in CRC survivors than in the general population (SIR males 1.14, 95% confidence interval [CI] 1.12-1.17, AER = 24.7; SIR females 1.20, 95% CI 1.17-1.23, AER = 22.8). Increased risks of SPCs were observed for the digestive system, urinary system and female and male reproductive organs. CRC incidence increased in younger persons (<50 years) and SPC incidence was 4-fold in this group (SIR males 4.51, 95% CI 4.04-5.01, AER = 64.2; SIR females 4.03, 95% CI 3.62-4.48, AER = 77.0). Primary tumor-related factors associated with SPC risk were right-sided cancer and smaller primary tumor size. Treatment and risk of SPC differed for CC (no effect) and RC (lower risk after chemotherapy). CRC survivors have excess risk of developing SPC, with particular characteristics that could guide targeted surveillance.

Splenic flexure cancer: is right extended hemicolectomy better than left hemicolectomy?

INTRODUCTION

There is no consensus on the optimal surgery for splenic flexure cancers.

METHODS

Review of a prospectively maintained database of patients with splenic flexure cancer undergoing either a right extended hemicolectomy or left hemicolectomy at a tertiary care cancer hospital from 14.5.2010 to 16.9.2021. The primary outcome measures were postoperative morbidity and hospital stay with secondary outcomes being overall survival, disease-free survival, and long-term patient reported functional and quality of life outcomes.

RESULTS

The demographic variables were evenly distributed between groups, and median follow-up was 44 months. The groups were comparable in terms of postoperative morbidity (Clavien-Dindo complication ≥ 3a 10.6% vs 10%, p = 0.322) and hospital stay (8 days vs 7 days, p = 0.316). Oncological outcomes were similar in both groups (3-year disease-free survival 71.8% vs 67.8%, p = 0.877, and 3-year overall survival 83.9% vs 75.8%, p = 0.787), and long-term patient-reported functional outcomes were excellent in both groups.

CONCLUSION

Oncological outcomes, post operative morbidity, and long-term patient reported functional outcomes are comparable in patients undergoing either a right extended or left hemicolectomy for splenic flexure cancer.

Molecular Characteristics of Early-Onset Colorectal Cancer According to Detailed Anatomical Locations: Comparison With Later-Onset Cases

INTRODUCTION

Early-onset colorectal cancer diagnosed before the age of 50 years has been increasing. Likely reflecting the pathogenic role of the intestinal microbiome, which gradually changes across the entire colorectal length, the prevalence of certain tumor molecular characteristics gradually changes along colorectal subsites. Understanding how colorectal tumor molecular features differ by age and tumor location is important in personalized patient management.

METHODS

Using 14,004 cases with colorectal cancer including 3,089 early-onset cases, we examined microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and KRAS and BRAF mutations in carcinomas of the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum and compared early-onset cases with later-onset cases.

RESULTS

The proportions of MSI-high, CIMP-high, and BRAF -mutated early-onset tumors were lowest in the rectum (8.8%, 3.4%, and 3.5%, respectively) and highest in the ascending colon (46% MSI-high; 15% CIMP-high) or transverse colon (8.6% BRAF -mutated) (all Ptrend <0.001 across the rectum to ascending colon). Compared with later-onset tumors, early-onset tumors showed a higher prevalence of MSI-high status and a lower prevalence of CIMP-high status and BRAF mutations in most subsites. KRAS mutation prevalence was higher in the cecum compared with that in the other subsites in both early-onset and later-onset tumors ( P < 0.001). Notably, later-onset MSI-high tumors showed a continuous decrease in KRAS mutation prevalence from the rectum (36%) to ascending colon (9%; Ptrend <0.001), followed by an increase in the cecum (14%), while early-onset MSI-high cancers showed no such trend.

DISCUSSION

Our findings support biogeographical and pathogenic heterogeneity of colorectal carcinomas in different colorectal subsites and age groups.

Prognostic role of detailed colorectal location and tumor molecular features: analyses of 13,101 colorectal cancer patients including 2994 early-onset cases

BACKGROUND

The pathogenic effect of colorectal tumor molecular features may be influenced by several factors, including those related to microbiota, inflammation, metabolism, and epigenetics, which may change along colorectal segments. We hypothesized that the prognostic association of colon cancer location might differ by tumor molecular characteristics.

METHODS

Utilizing a consortium dataset of 13,101 colorectal cancer cases, including 2994 early-onset cases, we conducted survival analyses of detailed tumor location stratified by statuses of microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and KRAS and BRAF oncogenic mutation.

RESULTS

There was a statistically significant trend for better colon cancer-specific survival in relation to tumor location from the cecum to sigmoid colon (Ptrend = 0.002), excluding the rectum. The prognostic association of colon location differed by MSI status (Pinteraction = 0.001). Non-MSI-high tumors exhibited the cecum-to-sigmoid trend for better colon cancer-specific survival [Ptrend < 0.001; multivariable hazard ratio (HR) for the sigmoid colon (vs. cecum), 0.80; 95% confidence interval (CI) 0.70-0.92], whereas MSI-high tumors demonstrated a suggestive cecum-to-sigmoid trend for worse survival (Ptrend = 0.020; the corresponding HR, 2.13; 95% CI 1.15-3.92). The prognostic association of colon tumor location also differed by CIMP status (Pinteraction = 0.003) but not significantly by age, stage, or other features. Furthermore, MSI-high status was a favorable prognostic indicator in all stages.

CONCLUSIONS

Both detailed colonic location and tumor molecular features need to be accounted for colon cancer prognostication to advance precision medicine. Our study indicates the important role of large-scale studies to robustly examine detailed colonic subsites in molecular oncology research.

Cancer Prevention for Survivors: Incidence of Second Primary Cancers and Sex Differences-A Population-Based Study from an Italian Cancer Registry

BACKGROUND

The number of cancer survivors continues to increase, thanks to advances in cancer diagnosis and treatment. Unfortunately, the incidence of a second primary cancer (SPC) is also increasing, but limited studies reporting incidence data are available regarding multiple cancers. This study presents our observations on multiple primary malignant cancers, the associations between sites, and the inherent sex differences.

PATIENTS AND METHODS

We report the data, disaggregated by sex, concerning the SPCs that were recorded in the "Registro Tumori Integrato" (RTI) a population-based cancer registry in Sicily, Italy, as observed in the period from 2003 to 2017, in a total population of approximately 2,300,000. SPCs were divided into synchronous and metachronous cancers. The International Classification of Diseases for Oncology, third edition (ICD-O-3), was used for topographical and morphological classifications. Multiple primary cancers with multi-organ primitiveness were selected from the database of the RTI by extracting patients with more than one diagnosis. SPCs had different histology or morphology from the particular cancer that was considered to be the index cancer case. Multicenter or multifocal cancers, or metastases, were excluded. The percentages of cancer by sex and topography, the average age of incidence, and a breakdown by age were computed.

RESULTS

Differences were observed between sexes in terms of incidence and site for SPCs. The most frequent SPC was skin cancer (20% of the SPCs observed). The associations among sites of multiple cancers are reported.

CONCLUSION

There are many gaps in our knowledge of sex differences in cancer. The study of multiple primary cancers could bring more likely opportunities for evaluation of the cancer burden and trends that can be used to identify new research areas by population health programs, as well as for clinical researchers.

Detection and Yield of Colorectal Cancer Surveillance in Adults with PTEN Hamartoma Tumour Syndrome

Colorectal cancer surveillance (CCS) with colonoscopy every five years is advised for PTEN Hamartoma Tumour Syndrome (PHTS) patients aged ≥40 due to an increased colorectal cancer (CRC) risk. However, data to support CCS guidelines are scarce and available CRC risks are low (0-5% at age 50) and likely overestimated. We aimed to assess the detection and yield of CCS for PHTS patients without a CRC history. A retrospective cohort study including PHTS patients aged ≥40 with CCS at a PHTS expertise centre between 2011 and 2022. Adenomas with a ≥10 mm size, (tubulo)villous histology, or high-grade dysplasia were considered advanced. During 67 follow-up years, 37 patients (median age 47 years) underwent 61 colonoscopies. CCS yielded no CRCs. Adenomas were diagnosed in 13/37 (35%) patients during 23/100 colonoscopies (95% CI: 14-36), including one advanced adenoma. Baseline adenoma detection rates were similar to follow-up and higher in patients aged above 50 (50/100, 95% CI: 24-76) vs. age 50 or below (11/100, 95% CI: 3-30; p = 0.021). The low CRC and advanced adenoma yield allow for a more personalised surveillance program. Following our findings combined with literature on CRC risk and progression, we suggest starting CCS at age 40 with variable follow-up intervals between 1 and 10 years depending on previous colonoscopy findings.

Primary ovarian cancer after colorectal cancer: a Dutch nationwide population-based study

BACKGROUND AND PURPOSE

Women with colorectal cancer (CRC) are at risk not only of developing ovarian metastases, but also of developing a primary ovarian malignancy. Several earlier studies have in fact shown a link between the development of primary ovarian cancer and CRC. The purpose of this study was therefore to determine the risk of developing a primary ovarian cancer in women with prior CRC compared to the general population.

METHODS

Data from the Netherlands Cancer Registry were used. All women diagnosed with invasive CRC between 1989 and 2017 were included. Standardized incidence ratios (SIRs) and absolute excess risks (AERs) per 10,000 person-years were calculated.

RESULTS

During the study period, 410 (0.3%) CRC patients were diagnosed with primary ovarian cancer. Women with CRC had a 20% increased risk of developing ovarian cancer compared to the general population (SIR = 1.2, 95% CI: 1.1-1.3). The AER of ovarian cancer was 0.9 per 10,000 person-years. The risk was especially increased within the first year of a CRC diagnosis (SIR = 3.3, 95% CI: 2.8-3.8) and in women aged ≤ 55 years (SIR = 2.0, 95% CI: 1.6-2.6).

CONCLUSION

This study found a slightly increased risk of primary ovarian cancer in women diagnosed with CRC compared to the general population. However, this may be partly attributable to surveillance or detection bias. Nevertheless, our findings could be helpful for patient counseling, as CRC patients do not currently receive information concerning the increased risk of ovarian cancer.

Risk of extracolonic second primary cancers following a primary colorectal cancer: a systematic review and meta-analysis

PURPOSE

The purpose of the study is to assess the global risk of extracolonic secondary primary cancers (SPCs) in patients with colorectal cancer (CRC).

METHODS

Studies of SPC in patients with CRC were included if they reported the standardised incidence ratio (SIR) for extracolonic SPCs in patients with CRC compared with the general population. Pooled summary estimates were calculated using a random-effects model.

RESULTS

A total of 7,716,750 patients with CRC from 13 retrospective cohort studies that reported extracolonic SPC incidence were included. The overall risk of several SPCs was significantly higher in patients with CRC compared with the general population, including cancers of the urinary bladder (pooled SIR 1.19, 95% confidence interval (CI) 1.06-1.33; p = 0.003), female genital tract (1.88, 1.07-3.31; p = 0.03), kidney (1.50, 1.19-1.89; p = 0.0007), thorax (lung, bronchus and mediastinum) (1.16, 1.01-1.32; p = 0.03), small intestine (4.26, 2.58-7.01; p < 0.0001), stomach (1.22, 1.07-1.39; p = 0.003), and thyroid (1.40, 1.28-1.53; p < 0.0001), as well as melanoma (1.28, 1.01-1.62; p = 0.04). There was also a decreased risk of developing cancer of the gall bladder (0.75, 0.60-0.94; p = 0.01).

CONCLUSION

Patients with CRC had a significantly increased risk of extracolonic SPCs compared with the general population. These findings highlight the need to develop research strategies for the management of second primary cancer in patients with CRC.

What Is the Optimal Elective Colectomy for Splenic Flexure Cancer: End of the Debate? A Multicenter Study From the GRECCAR Group With a Propensity Score Analysis

BACKGROUND

The optimal elective colectomy in patients with splenic flexure tumor is debated.

OBJECTIVE

This study aimed to compare splenic flexure colectomy, left hemicolectomy, and subtotal colectomy for perioperative, histological, and survival outcomes in this setting.

DESIGN

This is a multicenter retrospective cohort study.

SETTING

Patients diagnosed with nonmetastatic splenic flexure tumor who underwent elective colectomy were included.

PATIENTS

Between 2006 and 2014, 313 consecutive patients were operated on in 15 French Research Group of Rectal Cancer Surgery centers.

INTERVENTIONS

Propensity score weighting was performed to compare short- and long-term outcomes.

MAIN OUTCOME MEASURES

The primary end point was disease-free survival. Secondary end points included overall survival, quality of surgical resection, overall postoperative morbidity, surgical postoperative morbidity, and rate of anastomotic leakage.

RESULTS

The most performed surgery was splenic flexure colectomy (59%), followed by subtotal colectomy (23%) and left hemicolectomy (18%). Subtotal colectomy was more often performed by laparotomy compared with splenic flexure colectomy and left hemicolectomy (93% vs 61% vs 56%, p < 0.0001), and was associated with a longer operative time (260 minutes (120-460) vs 180 minutes (68-440) vs 217 minutes (149-480), p < 0.0001). Postoperative morbidity was similar between the 3 groups, but the median length of hospital stay was significantly longer after subtotal colectomy (13 days (5-56) vs 10 (4-175) vs 9 (4-55), p = 0.0007). The median number of harvested lymph nodes was significantly higher after subtotal colectomy compared with splenic flexure colectomy and left hemicolectomy (24 (8-90) vs 15 (1-81) vs 16 (3-52), p < 0.0001). The rate of stage III disease and the number of patients treated by adjuvant chemotherapy were similar between the 3 groups. There was no difference in terms of disease-free survival and overall survival between the 3 procedures.

LIMITATIONS

The study was limited by its retrospective design.

CONCLUSIONS

In the elective setting, splenic flexure colectomy is safe and oncologically adequate for patients with nonmetastatic splenic flexure tumor. However, given the oncological clearance after splenic flexure colectomy, it seems that the debate is not completely closed. See Video Abstract at http://links.lww.com/DCR/B703.

CUL ES LA COLECTOMA ELECTIVA PTIMA PARA EL CNCER DE NGULO ESPLNICO FIN DEL DEBATE UN ESTUDIO MULTICNTRICO DEL GRUPO GRECCAR CON UN ANLISIS DE PUNTAJE DE PROPENSIN

ANTECEDENTES:La colectomía electiva óptima en pacientes con tumores del ángulo esplénico continua en debate.OBJETIVO:Comparar la colectomía de ángulo esplénico, hemicolectomía izquierda y colectomía subtotal para los resultados perioperatorios, histológicos y de supervivencia en este escenario.DISEÑO:Estudio de cohorte retrospectivo multicéntrico.ESCENARIO:Se incluyeron pacientes diagnosticados de tumores del ángulo esplénico no metastásicos que se sometieron a colectomía electiva.PACIENTES:Entre 2006 y 2014, 313 pacientes consecutivos fueron intervenidos en 15 centros GRECCAR.INTERVENCIONES:Se realizó una ponderación del puntaje de propensión para comparar los resultados a corto y largo plazo.PRINCIPALES MEDIDAS DE RESULTADO:El criterio de valoración principal fue la supervivencia libre de enfermedad. Los criterios de valoración secundarios incluyeron la supervivencia general, la calidad de la resección quirúrgica, la morbilidad posoperatoria general, la morbilidad posoperatoria quirúrgica y la tasa de fuga anastomótica.RESULTADOS:La cirugía más realizada fue la colectomía del ángulo esplénico (59%), seguida de la colectomía subtotal (23%) y la hemicolectomía izquierda (18%). La colectomía subtotal se realizó con mayor frecuencia mediante laparotomía en comparación con la colectomía de ángulo esplénico y la hemicolectomía izquierda (93% frente a 61% frente a 56%, p <0.0001), y se asoció con un tiempo quirúrgico más prolongado (260 min [120-460] frente a 180 min [68-440] frente a 217 min [149-480], p <0.0001). La morbilidad posoperatoria fue similar entre los tres grupos, pero la duración media de la estancia hospitalaria fue significativamente más prolongada después de la colectomía subtotal (13 días [5-56] frente a 10 [4-175] frente a 9 [4-55], p = 0.0007). La mediana del número de ganglios linfáticos extraídos fue significativamente mayor después de la colectomía subtotal en comparación con la colectomía del ángulo esplénico y la hemicolectomía izquierda (24 [8-90] frente a 15 [1-81] frente a 16 [3-52], p <0.0001). La tasa de enfermedad en estadio III y el número de pacientes tratados con quimioterapia adyuvante fueron similares entre los 3 grupos. No hubo diferencias en términos de supervivencia libre de enfermedad y supervivencia general entre los 3 procedimientos.LIMITACIONES:El estudio estuvo limitado por su diseño retrospectivo.CONCLUSIONES:En un escenario electivo, la colectomía del ángulo esplénico es segura y oncológicamente adecuada para pacientes con tumores del ángulo esplénico no metastásicos. Sin embargo, dado el aclaramiento oncológico tras la colectomía del ángulo esplénico, parece que el debate no está completamente cerrado. Consulte Video Resumen en http://links.lww.com/DCR/B703.

Metachronous small bowel adenocarcinoma after rectal adenocarcinoma: A case report

RATIONALE

Small bowel adenocarcinoma (SBA), an uncommon gastrointestinal malignant tumor, is difficult to diagnose at an early stage because of its non-specific disease presentation. Metachronous SBA is a special type of SBA that is rarely reported. We herein report a case of metachronous primary SBA following resection of rectal adenocarcinoma.

PATIENT CONCERNS

A 65-year-old man presented to our hospital after having experienced recurrent bowel obstruction for 6 months. He had undergone a Dixon operation 30 months previously followed by adjuvant chemotherapy with capecitabine plus oxaliplatin.

DIAGNOSIS

Abdominal computed tomography showed thickened bowel walls in the right lower abdomen, and the patient was initially misdiagnosed with intestinal adhesion. After the operation, he was diagnosed with primary SBA (T3N0M0, stage IIA).

INTERVENTIONS

Treatment with a transnasal ileus tube was ineffective. Therefore, we performed small intestinal segmental resection and side-to-side anastomosis through open surgery.

OUTCOMES

The patient completed all postoperative adjuvant chemotherapy, and posttreatment surveillance revealed no further abnormalities.

LESSONS

This case suggests that patients with colorectal adenocarcinoma may have an increased risk of metachronous SBA. Corresponding symptoms in high-risk patients should raise clinicians' suspicion for SBA, and further detailed examinations are imperative. Early screening for SBA may help to improve the patients' prognosis.

Second Primary Malignancies in Patients With Hepatocellular Carcinoma: A Population-Based Analysis

Background

Second primary malignancy (SPM) is becoming a threat for the health of cancer survivors. However, data on the features and results of patients with hepatocellular carcinoma (HCC) with SPMs are scarce. This study aimed to explore the characteristics of HCC patients with SPMs and to screen HCC patients who are at a high risk of developing SPMs.

Method

HCC patients diagnosed between 2000 and 2014 in the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively analyzed. Eligible patients were divided into the only one primary malignancy and SPM groups. The Fine-Gray proportional subdistribution hazards model was used to explore the risk factors of developing SPMs, and a competing-risk model was established to predict the probability of developing SPMs for HCC patients after initial diagnosis. The calibration curves, concordance index (C-index), and decision curve analysis (DCA) were used to evaluate the performance of the nomogram.

Results

A total of 40,314 HCC patients were identified, 1,593 (3.95%) of whom developed SPMs 2 months after the initial diagnosis with a maximum follow-up time of approximately 18 years. The 3-, 5-, and 10-year cumulative incidence of SPMs were 2.35%, 3.12%, and 4.51%, respectively. Age at initial diagnosis, extent of disease, tumor size, and treatment were identified as the independent risk factors of developing SPMs and integrated into the competing-risk nomogram. The C-index of the nomogram was 0.677 (95% confidence interval 0.676-0.678), and the calibration curves showed an excellent agreement between the nomogram prediction and the actual observations. Furthermore, DCA indicated that the nomogram had good net benefits in clinical scenarios.

Conclusions

HCC survivors remain at a high risk of developing SPMs. The development of SPMs was associated with the clinical features and treatment strategies. A competing-risk nomogram was constructed to help surgeons identify the patients who are at a high risk of developing SPMs and contribute to the further management of SPMs.

Patient and GP experiences of pathways to diagnosis of a second primary cancer: a qualitative study

Background

More people are surviving a first primary cancer and experiencing a second, different cancer. However, little is known about the diagnostic journeys of patients with second primary cancer (SPC). This study explores the views of patients and general practitioners (GPs) on their experiences of pathways to diagnosis of SPC, including the influence of a previous diagnosis of cancer on symptom appraisal, help-seeking and referral decisions.

Methods

Qualitative interviews with patients with a SPC diagnosis and case-linked GP interviews in a Scottish primary care setting. In-depth face to face or telephone interviews were conducted, underpinned by a social constructionist approach. Interviews were transcribed and Braun and Clarke’s thematic analysis undertaken. Three analysts from the research team read transcripts and developed the coding framework using QSR NVivo version 10, with input from a fourth researcher. Themes were developed from refined codes and interpreted in the context of existing literature and theory.

Results

Interviews were conducted with 23 patients (aged 43–84 years) with a SPC diagnosis, and 7 GPs. Five patient themes were identified: Awareness of SPC, symptom appraisal and help-seeking, pathways to diagnosis, navigating the healthcare system, and impact of SPC. GPs interviews identified: experience and knowledge of SPC and referrals and decision-making.

Conclusions

Insights into the pathway to diagnosis of SPC highlights the need for increased awareness of and vigilance for SPC among patients and healthcare providers (HCPs), and emotional support to manage the psychosocial burden.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08238-0.

The relationship among primary anatomic subsite and risk and distribution of second malignant neoplasms in patients with stage I/II diffuse large B-cell lymphoma: An analysis of the surveillance, epidemiology, and end results database

•

Diffuse large B-cell lymphoma(DLBCL) involving different primary extranodal sites have distinct clinicopathological characteristics and prognosis.

•

Patients with extranodal DLBCL have an increased risk of SMN than the US general population(SIR, 1.18; 95% CI, 1.11–1.26).

•

The risk of SMN significantly differs according to the location of DLBCL, age, sex and latency.

•

Different anatomical sites tend to develop different types of second tumors.

•

The strategies for cancer surveillance after extranodal DLBCL diagnosis may need to be individualized according to the subsite of extranodal DLBCL.

Background

Recent studies have reported that diffuse large B-cell lymphoma (DLBCL) involving different primary extranodal sites have distinct clinicopathological characteristics and prognosis. However, the risk of secondary malignant neoplasms (SMNs) in DLBCL survivors with different primary extranodal sites are unknown.

Methods

A total of 40,714 patients diagnosed with stage I/II DLBCL were included from the Surveillance, Epidemiology, and End Results (SEER) database from 1983 to 2015.The standardized incidence ratio (SIR) and absolute excess risk (AER) were used to assess the risk of SMNs.

Results

The results show that the risk of SMN was significantly higher in extranodal DLBCL than in the US general population (SIR, 1.18; 95% CI, 1.11–1.26), and the risk of developing SMN remains significantly elevated with increased latency. Moreover, there were multiple site-specific risk patterns. There was a 22%, 44%, 66%, 123% and 151% increased risk of SMN 10 years after primary gastrointestinal tract, head/neck, skeletal, lung and liver/pancreas DLBCL diagnosis, respectively. There was a significant decrease risk of SMN with increasing age at diagnosis for primary gastrointestinal tract and skeletal DLBCL. In addition, DLBCL patients with primary sites in the gastrointestinal tract, thyroid and liver/pancreas had the highest incidences of secondary stomach cancer, second thyroid cancer, and second hepatobiliary cancer, respectively, which indicated that the initial site of DLBCL may predict the type of SMN.

Conclusions

The strategies for cancer surveillance after extranodal DLBCL diagnosis may need to be individualized according to the subsite of extranodal DLBCL.

Rising incidence of early-onset colorectal cancer - a call to action

The incidence of early-onset colorectal cancer (CRC), which occurs in individuals <50 years of age, has been increasing worldwide and particularly in high-income countries. The reasons for this increase remain unknown but plausible hypotheses include greater exposure to potential risk factors, such as a Western-style diet, obesity, physical inactivity and antibiotic use, especially during the early prenatal to adolescent periods of life. These exposures can not only cause genetic and epigenetic alterations in colorectal epithelial cells but also affect the gut microbiota and host immunity. Early-onset CRCs have differential clinical, pathological and molecular features compared with later-onset CRCs. Certain existing resources can be utilized to elucidate the aetiology of early-onset CRC and inform the development of effective prevention, early detection and therapeutic strategies; however, additional life-course cohort studies spanning childhood and young adulthood, integrated with prospective biospecimen collections, omics biomarker analyses and a molecular pathological epidemiology approach, are needed to better understand and manage this disease entity. In this Perspective, we summarize our current understanding of early-onset CRC and discuss how we should strategize future research to improve its prevention and clinical management.

Identification of Metabolic-Associated Genes for the Prediction of Colon and Rectal Adenocarcinoma

Background and Aim

Uncontrolled proliferation is the most prominent biological feature of tumors. In order to rapidly proliferate, tumor cells regulate their metabolic behavior by controlling the expression of metabolism-related genes (MRGs) to maximize the utilization of available nutrients. In this study, we aimed to construct prognosis models for colorectal adenocarcinoma (COAD) and rectum adenocarcinoma (READ) using MRGs to predict the prognoses of patients.

Methods

We first acquired the gene expression profiles of COAD and READ from the TCGA database, and then utilized univariate Cox analysis, Lasso regression, and multivariable Cox analysis to identify the MRGs for risk models.

Results

Eight genes (CPT1C, PLCB2, PLA2G2D, GAMT, ENPP2, PIP4K2B, GPX3, and GSR) in the colon cancer risk model and six genes (TDO2, PKLR, GAMT, EARS2, ACO1, and WAS) in the rectal cancer risk model were identified successfully. Multivariate Cox analysis indicated that these two models could accurately and independently predict overall survival (OS) for patients with COAD or READ. Furthermore, functional enrichment analysis was used to identify the metabolism pathway of MRGs in the risk models and analyzed these genes comprehensively. Then, we verified the prognosis model in independent COAD cohorts (GSE17538) and detected the correlations of the protein expression levels of GSR and ENPP2 with prognosis for COAD or READ.

Conclusion

In this study, 14 MRGs were identified as potential prognostic biomarkers and therapeutic targets for colorectal cancer.

Risk of Second Primary Malignancies Based on the Histological Subtypes of Colorectal Cancer

Background: Previous studies have revealed an increased risk of second primary malignancies (SPMs) after colorectal cancer (CRC); however, no previous investigation has quantified differences in the risk of SPMs based on the histological subtypes of first primary CRC.

Methods: Patients diagnosed with first primary CRC between 2000 and 2011 were identified from the Surveillance, Epidemiology, and End Results cancer registries. The patients were divided into three cohorts: classical adenocarcinoma (CA), mucinous adenocarcinoma (MA), and signet-ring cell carcinoma (SRCC). Standardized incidence ratios were calculated to assess the risk of SPMs among the patients.

Results: Overall risk of SPMs was significantly higher among patients with three histological subtypes of CRC than in the general population. The risk of esophagus cancer was significantly increased in SRCC. The risk of small intestine, colon and rectum, and corpus uteri cancers was high in three histological subtypes, with the highest risk observed in SRCC, followed by MA. Increased risks of second stomach, uterus, urinary bladder, kidney, and thyroid cancers were only observed in CA patients, while increased risk of second renal pelvis cancer was limited to MA patients. Furthermore, the high overall risk of SPMs in CA patients persisted regardless of clinicopathological factors. After surgery combined with chemotherapy treatment, CA patients were more prone to developing second small intestine, colon and rectum cancers than those treated with surgery only. A lower second prostate cancer risk was observed in rectal CA patients treated with surgery combined with radiotherapy than in patients treated with surgery only.

Conclusion: The present study revealed that the risk of developing SPMs after CRC varied based on the histological subtypes of the first primary CRC. Although the mechanisms underlying the observed patterns of SPM risk remain unknown, the study provided insights into future cancer surveillance based on the histological subtypes of CRC.

Biphasic Expression of Atypical Chemokine Receptor (ACKR) 2 and ACKR4 in Colorectal Neoplasms in Association with Histopathological Findings

Facilitating resolution of inflammation using atypical chemokine receptors (ACKR) as an anticancer strategy is considered but requires a deeper understanding of receptor role in carcinogenesis. We aimed at transcriptional analysis (RTqPCR) of ACKR2 and ACKR4 expression in colorectal adenoma-adenocarcinoma sequence in paired normal-neoplastic tissues from 96 polyps and 51 cancers. On average, ACKR2 was downregulated in neoplastic as compared to non-affected tissue in polyp (by 2.7-fold) and cancer (by 3.1-fold) patients. The maximal downregulation (by 8.2-fold) was observed in adenomas with the highest potential for malignancy and was gradually lessening through cancer stages I-IV, owing to increased receptor expression in tumors. On average, ACKR4 was significantly downregulated solely in adenocarcinomas (by 1.5-fold), less so in patients with lymph node metastasis, owing to a gradual decrease in ACKR4 expression among N0-N1-N2 cancers in non-affected tissue without changes in tumors. In adenomas, ACKR4 downregulation in neoplastic tissue increased with increasing potential for malignancy and contribution of villous growth pattern. ACKR4 expression increased in non-affected tissue with a concomitant decrease in pathological mucosa. In conclusion, the changes in ACKRs expression occur already in precancerous colorectal lesions, culminating in the adenomas with the highest potential for malignancy. Therefore, chemoprevention by manipulating ACKRs’ expression is worth exploration.

Unexplained neoplastic anastomotic recurrence after right hemicolectomy: a case report

Background

Anastomotic recurrences of the colon are postulated to arise due to inadequate margins, tumor implantation by exfoliated cells, altered biological properties of bowel anastomosis, and missed synchronous lesions. In this paper, a case of unexpected early local recurrence after surgery for colon cancer is presented.

Case presentation

A 68-year-old Caucasian man underwent right hemicolectomy for invasive G2 adenocarcinoma. Two months later, endoscopy revealed a wide and well-functioning anastomosis with a hyperemic, hard, and thickened mucosal area of about 2 cm in diameter. Biopsies showed the presence of an adenocarcinoma with the same grading of the previous lesion. Ten days later, the patient underwent a new intervention; the last 10 cm of the ileum and half of the remaining transverse colon were resected, and the patient started adjuvant therapy. Specimen examination confirmed the presence of an adenocarcinoma (G2) penetrating the muscular layer of the wall; also, in this case, resection edges were free from tumoral invasion, and the removed lymph nodes were exempt from neoplastic colonization. The patient was seen in follow-up for about 5 years, and he did not show local or systemic manifestations.

Conclusions

Whenever a neoplastic recurrence on the anastomotic line occurs, in the presence of negative intestinal margins, as usual in right colectomies, the implantation of neoplastic cells could be the possible cause.

Risk Factor Profiles Differ for Cancers of Different Regions of the Colorectum

BACKGROUND & AIMS

The molecular features of colorectal tumors differ with their anatomic location. Colorectal tumors are usually classified as proximal or distal. We collected data from 3 cohorts to identify demographic, clinical, anthropometric, lifestyle, and dietary risk factors for colorectal cancer (CRC) at 7 anatomic subsites. We examined whether the associations differ among refined subsites and whether there are trends in associations from cecum to rectum.

METHODS

We collected data from the Nurses' Health Study, Nurses' Health Study 2, and Health Professionals Follow-up Study (45,351 men and 178,016 women, followed for a median 23 years) on 24 risk factors in relation to risk of cancer in cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectosigmoid junction, and rectum. Hazard ratios were estimated using Cox proportional hazards regression. We tested for linear and nonlinear trends in associations with CRC among subsites and within proximal colon, distal colon, and rectum.

RESULTS

We documented 3058 cases of CRC (474 in cecum, 633 in ascending colon, 250 in transverse colon, 221 in descending colon, 750 in sigmoid colon, 202 in rectosigmoid junction, and 528 in rectum). The positive associations with cancer risk decreased, from cecum to rectum, for age and family history of CRC. In contrast, the inverse associations with cancer risk increased, from cecum to rectum, for endoscopic screening and intake of whole grains, cereal fiber, and processed red meat. There was a significant nonlinear trend in the association between CRC and female sex, with hazard ratios ranging from 1.73 for ascending colon cancer to 0.54 for sigmoid colon cancer. For proximal colon cancers, the association with alcohol consumption and smoking before age 30 years increased from the cecum to transverse colon. For distal colon cancers, the positive association with waist circumference in men was greater for descending vs sigmoid colon cancer.

CONCLUSIONS

In an analysis of 3058 cases of CRC, we found that risk factor profiles differed for cancers along the colorectum. Proximal vs distal classifications are not sufficient to encompass the regional variations in colorectal tumor features and risk factors.

Cadherins down-regulation: towards a better understanding of their relevance in colorectal cancer

The down-regulation of cadherin expression in colorectal cancer (CRC) has been widely studied. However, existing data on cadherin expression are highly variable and its relevance to CRC development has not been completely established. This review examines published studies on cadherins whose down-regulation has been already demonstrated in CRC, trying to establish a relationship with promoter methylation, the capacity to influence the Wnt / CTNNB1 (catenin beta 1, beta-catenin) signalling pathway and the clinical implications for disease outcome. Moreover, it also analyses factors that may explain data variability and highlights the importance of considering the altered subcellular localization of the examined cadherins. The results of this survey reveal that thirty of one hundred existing cadherins appear to be down-regulated in CRC. Among these, ten are cadherins, sixteen are protocadherins, equally divided between clustered and non clustered, and four are cadherin - related. These findings suggest that, to better define the role played by cadherin down-regulation in CRC pathogenesis, the expression of multiple rather than individual cadherins should be taken into account and further functional studies are necessary to clarify the relative ability of individual cadherins to inhibit CTNNB1 therefore acting as tumor suppressors.

Second Primary Malignancies in Patients with Colorectal Cancer: A Population-Based Analysis

Purpose

This study aimed to profile the characteristics of patients with colorectal cancer (CRC) with a second primary malignancy (SPM) and to identify patients with CRC at high risk of developing SPMs.

Methods

We retrospectively reviewed data on patients with CRC aged 20–79 years from the Surveillance, Epidemiology, and End Results (SEER) database. Eligible patients were categorized into only one primary malignancy and SPM cohorts. A competing‐risk model was used to quantify associations between SPM occurrence and the multiple traits of patients. Finally, a decision curve analysis (DCA) was used to evaluate the clinical usefulness of the model by calculating net benefit.

Results

A total of 179,884 patients were identified, 18,285 (10.2%) of whom developed SPMs during a maximum follow‐up of approximately 18 years. The median survival time after the second diagnosis was less than 4 years. The 3‐year, 5‐year, and 10‐year cumulative risks of developing an SPM were 3.9%, 5.9%, and 10.0%, respectively. According to the multivariable competing‐risk model, male colon cancer survivors, older in age, with a well‐differentiated tumor and localized disease, who were treated with surgery were susceptible to SPMs. The DCA yielded a wide range of risk thresholds at which the net benefits would be obtained from our proposed model.

Conclusion

CRC survivors remain at high risk of developing SPMs. Patients with a second diagnosis of cancer showed not only significantly worse survival but also higher cancer‐specific mortality. A web‐based individualized predictive tool was also provided to assist clinicians in identifying patients at high risk of developing SPMs and planning their future care management.

Implications for Practice

Colorectal cancer survivors remain at high risk of developing a second primary malignancy (SPM). This study aimed to profile the characteristics of patients with colorectal cancer with second primary malignancies and to further explore the risk factors related to the development of second primary malignancies, using a large population‐based cohort. A clinically useful competing‐risk nomogram was developed to predict the risk of SPMs based on individual clinical factors. According to the findings, older age, male sex, white or black race, localized disease, and treatment with surgery among patients with colon cancer were associated with an increased risk of developing an SPM. These findings and the proposed tool could be useful to clinicians and caregivers in the clinical counseling of patients with colorectal cancer and the development of long‐term care management.

Little is known about the factors that contribute to the development of a new malignancy among colorectal cancer survivors. This study aimed to comprehensively profile the characteristics of patients with colorectal cancer with a second primary malignancy and, further, to identify patients at high risk for developing a second primary malignancy.

[Second Primary Cancer after Treating Gastrointestinal Cancer]

Advances in diagnosis and therapeutic technologies have brought increased life expectancy for most cancers, but paradoxically it also has increased the risk of second primary malignancies. Cancer survivors have a higher risk of developing cancer than the general population. This suggests that more studies are needed to develop screen and management programs for cancer survivors, especially patients with gastrointestinal cancers, which are the most common cancers in Korea.

Reevaluation of a rightward shift in colorectal cancer: A single-center retrospective study in Tianjin

OBJECTIVES

Some Western reports have shown a proximal shift in colorectal cancer (CRC), but there are few studies in China. This study aimed to provide more information for the management and screening of CRC by investigating trends in the anatomic distribution of CRC among the Chinese population in recent years.

METHODS

A retrospective study was conducted on patients with CRC admitted to the Digestive Endoscopy Center of Tianjin Medical University General Hospital between January 2000 and December 2017. Patients were divided into a left-sided colorectal cancer (LSCRC) group and a right-sided colon cancer (RSCC) group. The detection rates of LSCRC and RSCC based on patients' age and sex, and on the time periods were analyzed.

RESULTS

A total of 2319 cases were diagnosed with CRC among 75 183 consecutive patients. The prevalence of CRC showed a significant reduction from 2000-2008 to 2009-2017 (3.8% vs 2.7%, P < .001). The proportion of RSCC presented a downtrend from 2000-2008 to 2009-2017 (40.6% vs 37.7%, P > .05). There were slightly more RSCCs in female patients than in male patients, with no significant difference (40.9% vs 36.5%, P > .05). The proportion of RSCC in patients aged ≥50 years was similar to that in younger patients. The alarming symptoms between LSCRC and RSCC showed a significant difference (P < .05).

CONCLUSIONS

In the present study, the prevalence of CRC declined significantly with time. However, there did not appear to be a rightward shift in CRC among the patients in Tianjin over the past 18 years.

Oral Bacteria and Intestinal Dysbiosis in Colorectal Cancer

The human organism coexists with its microbiota in a symbiotic relationship. These polymicrobial communities are involved in many crucial functions, such as immunity, protection against pathogens, and metabolism of dietary compounds, thus maintaining homeostasis. The oral cavity and the colon, although distant anatomic regions, are both highly colonized by distinct microbiotas. However, studies indicate that oral bacteria are able to disseminate into the colon. This is mostly evident in conditions such as periodontitis, where specific bacteria, namely Fusobacterium nucrelatum and Porphyromonas gingivalis project a pathogenic profile. In the colon these bacteria can alter the composition of the residual microbiota, in the context of complex biofilms, resulting in intestinal dysbiosis. This orally-driven disruption promotes aberrant immune and inflammatory responses, eventually leading to colorectal cancer (CRC) tumorigenesis. Understanding the exact mechanisms of these interactions will yield future opportunities regarding prevention and treatment of CRC.

Decreasing Trends of Secondary Primary Colorectal Cancer among Women with Uterine Cancer: A Population-Based Analysis

The current study examined trends, characteristics, and outcomes of women with uterine cancer who had secondary colorectal cancer. This is a retrospective study utilizing the Surveillance, Epidemiology, and End Results Program between 1973-2013. Among uterine cancer (n = 246,272) and colorectal cancer (n = 421,312) cohorts, women with both diagnoses were identified, and clinico-pathological factors and survival were extracted and analyzed. There were 6862 women with both cancer diagnoses, representing 2.8% of the uterine cancer cohort and 1.6% of the colorectal cancer cohort. Among 123,940 women with uterine cancer survivors, the number with postcedent colorectal cancer decreased from 5.3% to 0.7% between 1981-2008 (relative risk reduction 87.0% p < 0.001). Similarly, of 141,801 women with colorectal cancer survivors, the number with postcedent uterine cancer decreased from 1.7% to 0.5% between 1973-2008 (relative risk reduction 71.6%, p < 0.001). In the uterine cancer cohort, women with antecedent/synchronous colorectal cancer had more high-grade tumors and advanced-stage disease resulting in poorer survival, whereas those who had postcedent colorectal cancer had more low-grade tumors and early-stage disease resulting in superior survival compared to those without secondary colorectal cancer (all, p < 0.05). In conclusion, the development of postcedent colorectal cancer following uterine cancer has decreased in recent years in the United States.

Metastatic Profile of Colorectal Cancer: Interplay Between Primary Tumor Location and KRAS Status

BACKGROUND

Mutant KRAS tumors are purported to metastasize differently than wild-type KRAS tumors. The biological heterogeneity of tumors from different parts of the colon are also reported to affect metastasis. This study aims to characterize the metastatic profile by evaluating these factors in unison.

METHODS

Retrospective analysis of 899 patients with metastatic colorectal cancers treated from January 2010 to December 2014 was conducted. KRAS mutation status and primary tumors location were correlated with single-site metastasis (liver, lung, and peritoneum) and dual-site metastases (liver-peritoneum, liver-lung, and lung-peritoneum). Patients without KRAS analyses were excluded.

RESULTS

Right-sided tumors had highest frequency of peritoneal metastasis as compared to left-sided or rectal tumors (34.7% versus 15.8% versus 8.8%, P = 0.00) regardless of KRAS status (32.6% versus 38.5%, P = 0.62). Left-sided tumors with wild-type KRAS had greater proportion of liver metastasis (78.6% versus 53.5%, P = 0.00), whereas those with mutant KRAS had greater proportion of lung metastasis (23.3% versus 8.7%, P = 0.02). Rectal tumors with wild-type KRAS tend to spread to the liver (81.4% versus 48.0%, P = 0.00) and not to the peritoneum (2.3% versus 20.0%, P = 0.01). In dual-site metastases, left-sided tumors with wild-type KRAS had more liver-peritoneal metastases (75.0% versus 29.4%, P = 0.00), whereas mutant KRAS had greater lung-liver metastases (64.7% versus 20.8%, P = 0.01). Rectal tumors had the predilection for lung-liver metastases as compared to right-sided and left-sided tumors (92.3% versus 40.0% versus 39.0%, P = 0.00) regardless of KRAS status (100% versus 75%, P = 0.12).

CONCLUSIONS

Our results may streamline surveillance programs based on primary tumor location and KRAS mutational status.

Insights into Pathogenic Interactions Among Environment, Host, and Tumor at the Crossroads of Molecular Pathology and Epidemiology

Evidence indicates that diet, nutrition, lifestyle, the environment, the microbiome, and other exogenous factors have pathogenic roles and also influence the genome, epigenome, transcriptome, proteome, and metabolome of tumor and nonneoplastic cells, including immune cells. With the need for big-data research, pathology must transform to integrate data science fields, including epidemiology, biostatistics, and bioinformatics. The research framework of molecular pathological epidemiology (MPE) demonstrates the strengths of such an interdisciplinary integration, having been used to study breast, lung, prostate, and colorectal cancers. The MPE research paradigm not only can provide novel insights into interactions among environment, tumor, and host but also opens new research frontiers. New developments-such as computational digital pathology, systems biology, artificial intelligence, and in vivo pathology technologies-will further transform pathology and MPE. Although it is necessary to address the rarity of transdisciplinary education and training programs, MPE provides an exemplary model of integrative scientific approaches and contributes to advancements in precision medicine, therapy, and prevention.

Second primary malignancy risk after radiotherapy in rectal cancer survivors

AIM

To investigate second primary malignancy (SPM) risk after radiotherapy in rectal cancer survivors

METHODS

We used Taiwan’s National Health Insurance Research Database to identify rectal cancer patients between 1996 and 2011. Surgery-alone, preoperative short course, preoperative long course, and post-operative radiotherapy groups were defined. The overall and site-specific SPM incidence rates were compared among the radiotherapy groups by multivariate Cox regression, taking chemotherapy and comorbidities into account. Sensitivity tests were performed for attained-year adjustment and long-term survivors analysis.

RESULTS

A total of 28220 patients were analyzed. The 10-year cumulative SPM incidence was 7.8% [95% confidence interval (CI): 7.2%-8.2%] using a competing risk model. The most common sites of SPM were the lung, liver, and prostate. Radiotherapy was not associated with increased SPM risk in multi-variate Cox model (hazard ratio = 1.05, 95%CI: 0.91-1.21, P = 0.494). The SPM hazard remained unchanged in 10-year-survivors. In addition, no SPM risk difference was found between the preoperative radiotherapy and postoperative radiotherapy groups.

CONCLUSION

In this large population-based cohort study, we demonstrated that radiotherapy had no increase in SPM.

Risk of Synchronous and Metachronous Colorectal Cancer: Population-Based Estimates in Denmark with Focus on Non-Hereditary Cases Diagnosed After Age 50

BACKGROUND AND AIMS

The risk of synchronous and metachronous colorectal cancer is influenced by heritable and environmental factors. As a basis for comparative studies, we provide population-based estimates of synchronous and metachronous colorectal cancer with a focus on non-heritable cases.

MATERIAL AND METHODS

Based on data from national Danish cancer registers, we estimated the proportion of synchronous colorectal cancer and the incidence rates and risks for metachronous colorectal cancer in 28,504 individuals, who developed 577 metachronous colorectal cancer above age 50.

RESULTS

Synchronous colorectal cancer was diagnosed in 1.3% of the cases. The risk of metachronous colorectal cancer was associated with sex, tumor location, and age with the strongest influence from the latter. The incidence rate ratios for metachronous colorectal cancer ranged from above 6 in patients below age 65 to <1-3.2 in patients above age 65. The absolute risk of metachronous colorectal cancer was ⩾10% in patients below age 65 and 1.0%-8.0% in patients above age 65.

CONCLUSION

Individuals who develop sporadic, non-inherited colorectal cancer above age 50 are at a significantly increased risk of metachronous colorectal cancer with risk estimates that are strongly affected by age. This observation underscores the need for development of targeted surveillance in the most common clinical subset of colorectal cancer.

Do Patients with Second Primary Colorectal Cancer Hold the Similar Prognosis and Therapeutic Benefits as Those with Initial Primary Colorectal Cancer?

Aim

The objective is to compare the differences on prognosis and the therapeutic benefits between initial and second primary colorectal cancer (pCRC).

Methods

A dataset containing 377,271 initial pCRC cases and 18,617 second pCRC cases from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) 1988-2015 was evaluated. Survival comparisons were made using the log-rank test. Cox proportional hazards models were used to assess the survival benefits.

Results

The cancer-specific survival rate of patients with initial pCRC was significantly higher than that of patients with second pCRC (5-years survival rate: 64.85% vs. 60.22%, P<0.001). The Chi-square of stratified log rank for age at diagnosis was lower than that for primary site, pTNM stage, sex, race, histology, and grade (Chi-square=86.73). There were almost no differences on therapeutic benefits between patients with initial and second pCRC except that treatments with chemotherapy were significantly associated with longer survival rate compared with treatments without chemotherapy among stage III surgical initial and second primary left-sided colon cancers patients (HR=0.764 vs. 0.581; P for interaction =0.008).

Conclusion

Patients with second pCRC have worse prognosis than those with initial pCRC primarily because of older age in the former group. The results evidenced that the therapeutic benefits on the prognosis for colorectal cancer were generally similar between patients with initial and second pCRC.

Integrative analysis of exogenous, endogenous, tumour and immune factors for precision medicine

Immunotherapy strategies targeting immune checkpoints such as the CTLA4 and CD274 (programmed cell death 1 ligand 1, PD-L1)/PDCD1 (programmed cell death 1, PD-1) T-cell coreceptor pathways are revolutionising oncology. The approval of pembrolizumab use for solid tumours with high-level microsatellite instability or mismatch repair deficiency by the US Food and Drug Administration highlights promise of precision immuno-oncology. However, despite evidence indicating influences of exogenous and endogenous factors such as diet, nutrients, alcohol, smoking, obesity, lifestyle, environmental exposures and microbiome on tumour-immune interactions, integrative analyses of those factors and immunity lag behind. Immune cell analyses in the tumour microenvironment have not adequately been integrated into large-scale studies. Addressing this gap, the transdisciplinary field of molecular pathological epidemiology (MPE) offers research frameworks to integrate tumour immunology into population health sciences, and link the exposures and germline genetics (eg, HLA genotypes) to tumour and immune characteristics. Multilevel research using bioinformatics, in vivo pathology and omics (genomics, epigenomics, transcriptomics, proteomics and metabolomics) technologies is possible with use of tissue, peripheral blood circulating cells, cell-free plasma, stool, sputum, urine and other body fluids. This immunology-MPE model can synergise with experimental immunology, microbiology and systems biology. GI neoplasms represent exemplary diseases for the immunology-MPE model, given rich microbiota and immune tissues of intestines, and the well-established carcinogenic role of intestinal inflammation. Proof-of-principle studies on colorectal cancer provided insights into immunomodulating effects of aspirin, vitamin D, inflammatory diets and omega-3 polyunsaturated fatty acids. The integrated immunology-MPE model can contribute to better understanding of environment-tumour-immune interactions, and effective immunoprevention and immunotherapy strategies for precision medicine.

Subsite heterogeneity in the profiles of circulating cytokines in colorectal cancer

Colorectal cancers (CRCs) are treated as one entity but are in fact a heterogeneous group of diseases. If not addressed, subsite-associated variability may interfere with mechanism-targeted therapies and accuracy of potential CRC biomarkers. Little is known about the contribution of systemic inflammatory and immune mediators to subsite heterogeneity in CRC. Our purpose was to compare the profiles of key cytokines between right and left colonic and rectal CRCs. Using Luminex xMAP® technology, serum concentrations of eotaxin, IL-1β, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12(p70), IL-13, IL-15, IL-17, IFNγ, IP-10, FGF-2, G-CSF, GM-CSF, MCP-1, MIP-1α and β, PDGF-BB, RANTES, TNFα, and VEGF-A were determined in 104 CRC patients. We found the concentrations of IL-12(p70), IL-10, IL-1ra, IL-4, IL-6, IL-7, IL-8, G-CSF and TNFα to be significantly higher in right-sided and GM-CSF in left-sided than rectal CRCs. The concentrations of IFNγ and MIP-1α were significantly higher in right-sided CRCs as compared to cancers of other locations combined. In turn, MIP-1β was higher in rectal CRCs as compared to colon cancers. Taken together, our results show subsite heterogeneity of CRC cancers in terms of systemic inflammatory and immune responses that ought to be taken into account when attempting immunotherapy or developing biomarkers. Additionally, more pronounced T_H2 response accompanied by T_H1 immunity and more prominent tumor-promoting inflammation in CRC patients with primary tumors originating from right-sided colon may constitute a molecular background of unfavorable prognosis associated with this location.

Excessive risk of second primary cancers in young-onset colorectal cancer survivors

With an increasing trend of patients with young-onset colorectal cancer (CRC), risks of second primary cancers (SPCs) among them become a concerning issue. We aimed to define the detailed risk and site-distributed patterns of SPCs in young CRC individuals (age ≤50). A population-based cohort were identified from the Surveillance, Epidemiology, and End Results database between 1973 and 2013. Standardized incidence ratios (SIRs) and absolute excess risk (AER) were calculated to assess the risk for SPCs compared with the general population. A total of 44,106 patients, including 3245 (7.4%) the young and 40,861 (92.6%) the old, developed 50,679 secondary malignancies subsequently. With increased age, the risk of secondary cancers gradually decreased. A significant 44% excess risk of SPCs was observed in the young (SIR = 1.44, AER = 34.23), while a slightly increased risk was noted in the old (SIR = 1.02, AER = 4.29). For young survivors, the small intestine (SIR = 8.49), bile ducts (SIR = 3.77), corpus, and uterus (SIR = 2.45) were the most common sites of SPCs. Significantly, excess SIRs in the young were persisted regardless of other factors. For the young, secondary cancer-related deaths were responsible for 51.2% of overall deaths and secondary stomach, liver and bile, pancreas cancers were top three causes. An excessive risk of SPCs existed in young CRC survivors, and this trend was consistent among different subgroups. We hope our findings may inform future targeted screening strategies among young-onset CRC survivors.

Second primary colorectal cancer among endometrial cancer survivor: shared etiology and treatment sequelae

Purpose

To evaluate the incidence of colon cancer as a second primary cancer (CCSPC) and the survival outcomes of women with and without CCSPC after the diagnosis of endometrial cancer (EC).

Methods

The standardized incidence ratio (SIR) of CCSPC and survival outcomes of EC survivors with and without CCSPC were analyzed using data from January 1 1993 to December 31 2011, obtained from the Korea Central Cancer Registry.

Results

Of 14,797 EC survivors, 147 (0.99%) developed CCSPC after an average interval of 5.5 years. The SIR of CCSPC among EC survivors was 2.56, higher than that of colon cancer in the general population. The SIR of CCSPC was highest for the ascending (3.77), followed by the transverse (3.45), descending colon (2.06), and rectum (1.99). The risk of a proximal site of CCSPC was high, especially within 5 years after the diagnosis of EC in the ascending (SIR, 4.37) and transverse (4.91) colon, and in young survivors (< 60 years) in the ascending (5.19) and transverse (3.82) colon. The 5- and 10-year overall survival rates were 84.8 and 80.4% among survivors with EC only and 89.2 and 76.3% for survivors with CCSPC, respectively.

Conclusions

The risk of CCSPC among EC survivors increases especially in the proximal colon in young survivors. These results could be used for surveillance and counseling of EC survivors.

Secondary Primary Prostate Cancer after Colorectal Cancer: A Nationwide Population-based Cohort Study in Korea

Background

Colorectal cancer (CRC) and prostate cancer frequently occur in developed countries. There are several reports on the association between CRC and prostate cancer; however, the conclusions are inconsistent to investigate the association of the development of secondary primary prostate cancer among patients with prior primary CRC using a nationwide population-based dataset.

Methods

Patients registered in the Republic of Korea National Health Insurance System database who were diagnosed with CRC between 2007 and 2012 were followed-up until the end of 2015, and we investigated the new diagnosis secondary primary prostate cancer. We compared the incidence of prostate cancer in age-matched controls using the Cox proportional hazards models.

Results

We analyzed a total of 85,455 first primary CRC survivors. During the follow-up period of 494,222 person-years, 2,005 patients (2.30%) developed secondary primary prostate cancer (incidence rate 4.06/1,000 person-years). The median duration of follow-up was 5.78 years. Compared with the general population, CRC patients had a significantly increased risk of secondary primary prostate cancer (HR = 2.30, 95% CI = 2.18–2.43; P < 0.001). Multivariate analysis (including age, sex, body mass index, hypertension, diabetes mellitus, dyslipidemia, and income) showed that age < 55 years (HR = 20.74, 95% CI = 11.81–36.41; P < 0.001) is a significant independent predictor of secondary primary prostate cancer development.

Conclusions

Men diagnosed with colorectal cancer are at an increased risk of secondary primary prostate cancer, particularly those aged < 55 years. The data suggests that colorectal cancer patients aged < 55 years require regular screening for prostate cancer.

Pathways to diagnosis of a second primary cancer: protocol for a mixed-methods systematic review

INTRODUCTION

As cancer survivors continue to live longer, the incidence of second primary cancers (SPCs) will also rise. Relatively little is understood about the diagnostic pathway for SPCs, how people appraise, interpret symptoms and seek help for a second different cancer and the experiences (including challenges) of healthcare providers relating to SPCs. This study aims to systematically appraise and synthesise the literature on the pathways to diagnosis of an SPC and the associated patient and healthcare provider experiences.

METHODS

The approach taken includes systematic searches of published and unpublished literature without any date or language restrictions. MEDLINE, Embase, CAB Abstracts, MEDLINE In-Process and non-indexed citations, PsycINFO, Epub Ahead of Print, In-Process and other non-indexed citations, Ovid MEDLINE Daily, CINAHL, ASSIA, Sociological Abstracts, Web of Science, PROSPERO and grey literature will be searched to identify observational, systematic reviews, mixed methods and qualitative studies of interest. Titles, abstracts and full texts will be screened against the inclusion-exclusion criteria by at least two reviewers independently. Relevant outcomes of interest and study and population characteristics will be extracted. Synthesis will be used guided by the Pathways to Treatment model and the Olesen model of time intervals.

ETHICS AND DISSEMINATION

Ethical approval is not required. This systematic review will provide a deeper understanding of the complex and heterogeneous diagnostic pathways of SPCs, while identifying common themes across the diagnostic interval, routes to diagnosis and patient and healthcare provider experiences. These findings will help provide a nuanced picture of the diagnostic pathway for SPCs that may inform policy and consistent practice. In particular, approaches to early diagnosis for an SPC; including the timing and reasons behind the decision by the patient to seek care,the challenges faced by healthcare providers, and in the development of future interventions to reduce the delay in patient time-to-presentation.

PROSPERO REGISTRATION NUMBER

CRD42016051692.

Incidence of second tumors after treatment with or without radiation for rectal cancer

Background

The aim of this study was to analyze the association between radiation therapy (RT) for rectal cancer and the development of second tumors.

Patients and methods

Data on all surgically treated non-metastatic primary rectal cancer patients diagnosed between 1989 and 2007 were retrieved from the Netherlands population-based cancer registry. Fine and Gray's competing risk model was used for estimation of the cumulative incidence of second tumors. Multivariable analysis was conducted using Cox regression.

Results

The cohort consisted of 29 027 patients of which 15 467 patients had undergone RT. Median follow-up was 7.7 years (range 0-27). Among all 4398 patients who were diagnosed with a second primary tumor, 1030 had one or more pelvic tumors. The standardized incidence risk for any second tumor was 1.16 (95% confidence interval [CI] 1.12-1.19), resulting in 27.7/10 000 excess cancer cases per year in patients treated for rectal cancer compared with the general population. RT reduced the cumulative incidence of second pelvic tumors compared with patients who did not receive RT (subhazard ratio [SHR] 0.77, CI 0.68-0.88). Second prostate tumors were less common in patients who received RT (SHR 0.54, CI 0.46-0.64), gynecological tumors were more frequently observed in patients who received RT (SHR 1.49, CI 1.11-2.00).

Conclusions

Patients with previous rectal cancer had a marginally increased risk of a second tumor compared with the general population. Gynecological tumors occurred more often in females who received RT, but this did not result in an overall increased risk for a second cancer. RT even seemed to have a protective effect on the development of other second pelvic tumors, pre-dominantly for prostate cancer. These findings are highly important and can contribute to improved patient counseling.

Risk factors for metachronous colorectal cancer or polyp: A systematic review and meta-analysis

BACKGROUND AND AIM

We conducted a systematic review and meta-analysis to identify personal, lifestyle, and tumor-related risk factors for metachronous colorectal cancer (CRC) and polyp.

METHODS

Relevant studies were identified by searching MEDLINE, Web of Science and Cochrane Central Register through 15 May 2016. Estimates for associations were summarized using random effects models.

RESULTS

Fifty-five studies were included in the review. For individuals who had a CRC resection, having a synchronous polyp was a risk factor for metachronous CRC or polyp (relative risk [RR], 2.04; 95% confidence interval [CI], 1.48-2.82) and having a synchronous CRC (RR, 1.90; 95% CI, 1.25-2.91) and proximally located CRC (RR, 2.12; 95% CI, 1.24-3.64) were risk factors for metachronous CRC. For individuals who had a polypectomy, larger size (RR, 4.26; 95% CI, 2.11-8.57) or severe dysplasia of the initial polyp (RR, 5.15; 95% CI, 2.02-13.14), and having a synchronous polyp (RR, 2.52; 95% CI, 1.35-4.73) were risk factors for metachronous CRC; and a family history of CRC (RR, 1.90; 95% CI, 1.26-2.87), having a synchronous polyp (RR, 2.47; 95% CI, 1.74-3.50) and a larger size (RR, 1.49; 95% CI, 1.03-2.15) and proximal location of the initial polyp (RR, 1.20; 95% CI, 1.02-1.40) were risk factors for metachronous polyp. Meta-regression showed duration of follow-up was not a source of heterogeneity for most associations. There was no evidence that lifestyle factors were associated with metachronous CRC or polyp risk.

CONCLUSION

A comprehensive list of risk factors identified for metachronous CRC or polyp may have important clinical implications.

A Comprehensive Model of Colorectal Cancer by Risk Factor Status and Subsite Using Data From the Nurses' Health Study

We expanded and updated our colon cancer risk model to evaluate colorectal cancer (CRC) and whether subsite-specific risk models are warranted. Using data from 1980-2010 for 90,286 women enrolled in the Nurses' Health Study, we performed competing-risks regression and tests for subsite heterogeneity (proximal colon: n = 821; distal colon: n = 521; rectum: n = 376). Risk factors for CRC were consistent with those in our colon cancer model. Processed meat consumption was associated with a higher risk of distal (hazard ratio (HR) = 1.45; P = 0.02) but not proximal (HR = 0.95; P = 0.72) colon cancer. Smoking was associated with both colon (HR = 1.21) and rectal (HR = 1.27) cancer and was more strongly associated with proximal (HR = 1.31) than with distal (HR = 1.04) colon cancer (P = 0.029). We observed a significant trend of cancer risk for smoking in subsites from the cecum (HR = 1.41) to the proximal colon (excluding the cecum; HR = 1.27) to the distal colon (HR = 1.04; P for trend = 0.040). The C statistics for colorectal (C = 0.607), colon (C = 0.603), and rectal (C = 0.639) cancer were similar, although C was slightly higher for rectal cancer. Despite evidence for site-specific differences for several risk factors, overall our findings support the application of risk prediction models for colon cancer to CRC.

Fusobacterium nucleatum in Colorectal Carcinoma Tissue According to Tumor Location

Objectives:

Evidence suggests a possible role of Fusobacterium nucleatum in colorectal carcinogenesis, especially in right-sided proximal colorectum. Considering a change in bowel contents and microbiome from proximal to distal colorectal segments, we hypothesized that the proportion of colorectal carcinoma enriched with F. nucleatum might gradually increase along the bowel subsites from rectum to cecum.

Methods:

A retrospective, cross-sectional analysis was conducted on 1,102 colon and rectal carcinomas in molecular pathological epidemiology databases of the Nurses’ Health Study and the Health Professionals Follow-up Study. We measured the amount of F. nucleatum DNA in colorectal tumor tissue using a quantitative PCR assay and equally dichotomized F. nucleatum-positive cases (high vs. low). We used multivariable logistic regression analysis to examine the relationship of a bowel subsite variable (rectum, rectosigmoid junction, sigmoid colon, descending colon, splenic flexure, transverse colon, hepatic flexure, ascending colon, and cecum) with the amount of F. nucleatum.

Results:

The proportion of F. nucleatum-high colorectal cancers gradually increased from rectal cancers (2.5% 4/157) to cecal cancers (11% 19/178), with a statistically significant linear trend along all subsites (P<0.0001) and little evidence of non-linearity. The proportion of F. nucleatum-low cancers was higher in rectal, ascending colon, and cecal cancers than in cancers of middle segments.

Conclusions:

The proportion of F. nucleatum-high colorectal cancers gradually increases from rectum to cecum. Our data support the colorectal continuum model that reflects pathogenic influences of the gut microbiota on neoplastic and immune cells and challenges the prevailing two-colon (proximal vs. distal) dichotomy paradigm.

Increased Incidence of Second Primary Pancreatic Cancer in Patients with Prior Colorectal Cancer: A Population-Based US Study

BACKGROUND

Identifying high-risk groups for pancreatic cancer (PC) may lead to earlier detection. We determined the risk of subsequent PC among survivors of sporadic colorectal cancer (CRC).

METHODS

We evaluated data from the US Surveillance, Epidemiology, and End Results registry to identify individuals with primary CRC between the years 1973-2006. Standardized incidence ratios (SIRs) and 95 % confidence interval (95 % CI) were calculated to compare the risk of subsequent primary PC in the study cohort to that of the standard population. Analysis was stratified by age at diagnosis of CRC and sex. CRC characteristics were compared among CRC survivors with and without PC. Multivariate sub-hazard ratios were calculated to identify factors associated with subsequent primary PC, using death from non-PC causes as a competing event.

RESULTS

Of the 273,144 patients with first primary CRC, 657 (0.24 %) developed subsequent PC. CRC survivors were more likely to develop PC (SIR 1.22; 95 % CI 1.09-1.35). Mean latency period (time between CRC and PC diagnosis) was 1, 3, and 5 years from index age of CRC 20-49, 50-64, and >65 years, respectively. Multivariate analysis showed CRC survivors >50 years had 3.5-fold, those with right-sided CRC had 1.2-fold, and those with localized and regional CRCs had sixfold and fivefold increased risk of PC, respectively.

CONCLUSION

This study suggests that CRC survivors have an increased risk of developing subsequent PC within 1-5 years. CRC survivors age >50 with localized/regional stage, and right-sided CRC have higher predisposition to PC.

The Incidence Characteristics of Second Primary Malignancy after Diagnosis of Primary Colon and Rectal Cancer: A Population Based Study

Background

With the expanding population of colorectal cancer (CRC) survivors in the United States, one concerning issue is the risk of developing second primary malignancies (SPMs) for these CRC survivors. The present study attempts to identify the incidence characteristics of SPMs after diagnosis of first primary colon cancer (CC) and rectal cancer (RC).

Methods

189,890 CC and 83,802 RC cases were identified from Surveillance, Epidemiology and End Results Program (SEER) database. We performed rate analysis on incidence trend of SPMs in both CC and RC. Expected incidence rates were stratified by age, race and stage, calendar year of first CRC diagnosis and latency period since first CRC diagnosis. The standardized incidence ratios (SIRs), measure for estimating risk of SPMs, were calculated for CC and RC respectively.

Results

The trends of incidence of SPMs in both CC and RC were decreasing from 1992 to 2012. Both CC and RC survivors had higher risk of developing SPMs (SIRCC = 1.13; SIRRC = 1.05). For CC patients, the highest risks of SPM were cancers of small intestine (SIR = 4.03), colon (SIR = 1.87) and rectum (SIR = 1.80). For RC patients, the highest risks of SPMs were cancers of rectum (SIR = 2.88), small intestine (SIR = 2.16) and thyroid (SIR = 1.46). According to stratified analyses, we also identified incidence characteristics which were contributed to higher risk of developing SPMs, including the age between 20 and 40, American Indian/Alaska Native, localized stage, diagnosed at calendar year from 2002 to 2012 and the latency between 12 and 59 months.

Conclusions

Both CC and RC survivors remain at higher risk of developing SPMs. The identification of incidence characteristics of SPMs is extremely essential for continuous cancer surveillance among CRC survivors.

Incidence of Second Primary Malignancies Following Colorectal Cancer: A Distinct Pattern of Occurrence Between Colon and Rectal Cancers and Association of Co-Morbidity with Second Primary Malignancies in a Population-Based Cohort of 98,876 Patients in Taiwan

The purpose of this study is to determine the features of second primary malignancies (SPMs) among patients with prior colorectal cancer (CRC) using a nationwide population-based dataset.Patients with CRC newly diagnosed between 1996 and 2011, and >1 year of follow-up were recruited from the Taiwan National Health Insurance database. Standardized incidence ratios (SIRs) of SPMs in patients with CRC were calculated.During the 16-year study period, 4259 SPMs developed among 98,876 CRC patients. The median duration of follow-up was 4.03 years. The SIR for all SPMs was 1.13 (95% confidence interval = 1.10-1.17). Compared with the general population, a higher incidence of thyroid, prostate, ovarian, and hematologic malignancies developed among patients with colon cancer, whereas the risk for bone and soft tissue cancers increased among patients with rectal cancer. The risk for breast, bladder, kidney, lung, and uterine cancers was significantly higher in patients with colon and rectal cancers than the general population. The risk for liver and biliary tract cancers declined in patients with rectal cancer. Based on multivariate analysis among patients with CRC, age ≥70 years, men, chronic obstructive pulmonary disease (COPD), cirrhosis, and dyslipidemia were independent predictors of an SPM.In conclusion, patients with CRC were at increased risk for a second cancer. The pattern of SPMs was distinct between patients with colon and rectal cancer. Age, men, COPD, cirrhosis, and dyslipidemia were independent risk factors for SPMs. Surveillance and education should be provided for survivors with respect to risk for SPMs.

Familial colorectal cancer risk by subsite of primary cancer: a population-based study in Utah

BACKGROUND

Familial occurrence is common in colorectal cancer (CRC), but whether this increased familial risk differs by colonic subsite of the index patients CRC is not well understood.

AIM

To quantify the risk of CRC in first-degree (FDR), second-degree (SDR) and first cousin (FC) relatives of individuals with CRC, stratified by subsite in the colorectum and age at diagnosis.

METHODS

Colorectal cancers diagnosed between 1980 and 2010 were identified from the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. Age and gender-matched CRC-free controls were selected to form the comparison group for determining CRC risk in relatives using Cox regression analysis.

RESULTS

Of the 18,208 index patients diagnosed with CRC, 6584 (36.2%) were located in the proximal colon, 5986 (32.9%) in the distal colon and 5638 (31%) in the rectum. The elevated risk of CRC in relatives was similar in analysis stratified for CRC colorectal subsites in the index cases. FDR had similarly elevated risk of all site CRC, whether the index patient had cancer in the proximal colon [hazards ratio (HR): 1.85; 95% CI: 1.70-2.02], distal colon (HR: 1.90; 95% CI: 1.73-2.08) or rectum (HR: 1.83; 95% CI: 1.66-2.02) compared to relatives of controls. This risk was consistently greater for FDR when cases developed CRC below the age of 60 years.

CONCLUSIONS

Relatives of CRC patients have a similarly elevated risk of CRC regardless of colonic tumour subsite in the index patient, and it is greatest for relatives of younger age index cases.