Pathological features and survival outcomes of young patients with operable colon cancer: are they homogeneous?

Early-Onset Colorectal Cancer in Egypt: Pathological Characters, Patterns of Care, and Survival Compared to Average-Age Onset Colorectal Cancer: A Retrospective Multicenter Study

PURPOSE

Early-onset colorectal cancer (EOCRC) is a rising health problem. The incidence of EOCRC has increased over the past 2 decades all over the world. Reports from Egypt since the 1990s have reported a higher incidence among young populations with no identifiable risk factors. The aim of this study was to assess EOCRC in Egypt regarding incidence, characteristics, treatment pattern, and survival compared with average age onset and elderly patients.

MATERIALS AND METHODS

This was a retrospective, record-based, cohort study combining data from four different cancer centers in Egypt. We grouped patients according to age into three categories: the EOCRC group for patients age ≤45 years and the average age onset and elderly cancer group (for patients age ≥65 years).

RESULTS

The study included 1,310 patients with histopathologically proven colorectal cancer, representing four different geographical areas in Egypt. Patients with EOCRC represented 42.4% of the study population. Female patients were 50.6% among the EOCRC group and 52.5% among the average age group. Rectal tumors were significantly higher in EOCRC (54.7% v 40.6%; P < .001). There was no significant difference between both groups regarding the tumor stage at presentation, obstruction, or presence of metastases at presentation. Patients with EOCRC had a significantly higher rate of peritoneum/adnexa metastases than the average age ones (12.3% in EOCRC v 6.9% in the average age group; P < .001). No statistically significant differences between EOCRC and average age groups in both disease-free survival and overall survival were reported.

CONCLUSION

A comprehensive framework for the study of EOCRC is required in Egypt as well as a genomic analysis to identify possible underlying genetic alterations responsible for the high incidence of EOCRC.

Mismatch Repair Status Correlates with Survival in Young Adults with Metastatic Colorectal Cancer

BACKGROUND

Young adults with metastatic colorectal cancer (mCRC) may have higher rates of deficient mismatch repair (dMMR) than older patients. This study sought to assess patterns of MMR-testing and survival among young adult mCRC patients in the National Cancer Database (NCDB), hypothesizing that dMMR correlates with worse survival than in MMR-proficient (pMMR) patients.

METHODS

Stage-IV colorectal cancers were identified in NCDB (2010-2016). Demographic and clinical features were compared between younger (age ≤ 30) and older mCRC patients and tested for association with overall survival. Stage-IV disease without other recorded metastatic sites defined peritoneal metastasis (PM). Fisher-exact tests compared proportions and Cox models tested association with overall survival.

RESULTS

Of 124,587 stage-IV colorectal cancers, 1,123 (0.9%) were in young patients. Young patients were more likely to have mucinous histology, high-grade, rectal primaries, and isolated peritoneal metastases (P < 0.001). Younger patients more often had MMR-testing (29.1 versus 16.6%), with dMMR found at similar rates in young and older patients (21.7 versus 17.1% of those tested, P= 0.4). Despite higher rates of adverse prognostic features, younger patients had better survival (median 20.7 versus 14.8 months, P < 0.001). In MMR-tested patients, dMMR correlated with higher mortality risk compared to pMMR (median 16.6 months versus 25.5 months, P = 0.01). On multivariable analysis, grade and MMR-status remained independently associated with survival.

CONCLUSIONS

Median survival was worse with dMMR by 8.9 months compared to pMMR in young adults with mCRC. Despite higher rates of familial syndromes in young patients and recommendations for universal MMR-testing, over 70% of young mCRC patients had no MMR-status recorded.

Clinicopathologic and Racial/Ethnic Differences of Colorectal Cancer Among Adolescents and Young Adults

Despite overall reductions in colorectal cancer burden, incidence rates continue to rise among younger patients, and causes remain unknown. We examined differences in clinicopathologic and racial/ethnic characteristics within the adolescent and young adult (AYA) population diagnosed with colorectal cancer in the United States.

Molecular Analyses of Left- and Right-Sided Tumors in Adolescents and Young Adults with Colorectal Cancer

BACKGROUND

The incidence of colorectal cancer (CRC), particularly left-sided tumors (LT), in adolescents and young adults (AYA) is rising. Epigenetic events appear to play an important role in tumorigenesis and cancer progression, especially in younger patients. We compared molecular features of LT to right-sided tumors (RT) in AYA.

MATERIALS AND METHODS

A total of 246 LT and 56 RT were identified in a cohort of 612 AYA with primary CRC. Tumors were examined by next-generation sequencing (NGS), protein expression, and gene amplification. Tumor mutational burden (TMB) and microsatellite instability (MSI) were determined based on NGS data.

RESULTS

RT showed higher mutation rates compared with LT in several genes including BRAF (10.3% vs. 2.8%), KRAS (64.1% vs. 45.5%), PIK3CA (27% vs. 11.2%), and RNF43 (24.2% vs. 2.9%). Notably, additional mutations in distinct genes involved in histone modification and chromatin remodeling, as well as genes associated with DNA repair and cancer-predisposing syndromes, were characteristic of RT; most frequently KMT2D (27.8% vs. 3.4%), ARID1A (53.3% vs. 21.4%), MSH6 (11.1% vs. 2.3%), MLH1 (10.5% vs. 2.3%), MSH2 (10.5% vs. 1.2%), POLE (5.9% vs. 0.6%), PTEN (10.8% vs. 2.3%), and BRCA1 (5.4% vs. 0.6%). MSI was seen in 20.8% of RT versus 4.8% of LT. RT had a higher frequency of TMB-high regardless of MSI status.

CONCLUSION

Molecular profiling of AYA CRC revealed different molecular characteristics in RT versus LT. Epigenetic mechanisms and alteration in DNA repair genes warrant further investigation and may be a promising treatment target for CRC in AYA.

IMPLICATIONS FOR PRACTICE

Colorectal cancer (CRC) in adolescents and young adults (AYA) comprises a distinct entity with different clinicopathologic features and prognosis compared with older patients. Molecular profiling of right- and left-sided tumors in AYA is needed to gain novel insight into CRC biology and to tailor targeted treatment in this age group. This study found that right- and left-sided CRC show distinct molecular features in AYA, overall and in subgroups based on microsatellite instability status. Alterations in DNA double-strand break repair and homologous recombination repair, as well as epigenetic mechanisms, appear to play a critical role. The present molecular profiling data may support the development of personalized treatment strategies in the AYA population.

The Downregulation of lncRNA pgm5-as1 Inhibits the Proliferation and Metastasis Via Increasing miR-484 Expression in Colorectal Cancer

Background: Bioinformatics showed that long non-coding RNA (lncRNA) pgm5-as1 was regulated in patients with colorectal cancer (CRC), and miR-484 was also regulated in CRC. We aimed at determining the modulatory pathway of lncRNA pgm5-as1 in CRC cells, and whether miR-484 was involved in the pathway. Materials and Methods: The target gene of pgm5-as1 was predicted by bioinformatics and verified by dual luciferase assay. Transcription levels of pgm5-as1 and miR-484 were determined by quantitative real-time polymerase chain reaction. Viability, migration rate, invasion, and growth of SW480 and HCT116 cells were determined by Cell Counting Kit-8 (CCK-8), wound healing assay, transwell, and colony formation assay, respectively. Results: pgm5-as1 was upregulated in CRC tissues and cell lines; however, its downregulation contributed to the decreasing of cell viability, growth, migration, and invasion of SW480 and HCT116 cells. Moreover, miR-484 was predicted as the target of pgm5-as1, and the downregulation of pgm5-as1 partially restored the elevated cell viability, growth, migration, and invasion that were induced by the inhibition of miR-484 expression in SW480 and HCT116 cells. Conclusions: The loss of miR-484 expression in CRC might be involved in the promotion and metastasis of CRC, which may be caused by the overexpression of pgm5-as1. Hence, the downregulation of pgm5-as1 could be a therapeutic target in the prevention or intervention of CRC.

Impact of Patient Age on Molecular Alterations of Left-Sided Colorectal Tumors

BACKGROUND

The incidence of colorectal cancer (CRC) in younger patients is rising, mostly due to tumors in the descending colon and rectum. Therefore, we aimed to explore the molecular differences of left-sided CRC between younger (≤45 years) and older patients (≥65).

SUBJECTS, MATERIALS, AND METHODS

In total, 1,126 CRC tumor samples from the splenic flexure to (and including) the rectum were examined by next-generation sequencing (NGS), immunohistochemistry, and in situ hybridization. Microsatellite instability (MSI) and tumor mutational burden (TMB) were assessed by NGS.

RESULTS

Younger patients (n = 350), when compared with older patients (n = 776), showed higher mutation rates in genes associated with cancer-predisposing syndromes (e.g., Lynch syndrome), such as MSH6 (4.8% vs. 1.2%, p = .005), MSH2 (2.7% vs. 0.0%, p = .004), POLE (1.6% vs. 0.0%, p = .008), NF1 (5.9% vs. 0.5%, p < .001), SMAD4 (14.3% vs. 8.3%, p = .024), and BRCA2 (3.7% vs. 0.5%, p = .002). Genes involved in histone modification were also significantly more mutated: KDM5C (1.9% vs. 0%, p = .036), KMT2A (1.1% vs. 0%, p = .033), KMT2C (1.6% vs. 0%, p = .031), KMT2D (3.8% vs. 0.7%, p = .005), and SETD2 (3.2% vs. 0.9%, p = .039). Finally, TMB-high (9.7% vs. 2.8%, p < .001) and MSI-high (MSI-H; 8.1% vs. 1.9%, p = .009) were more frequent in younger patients.

CONCLUSION

Our findings highlight the importance of genetic counseling and screening in younger CRC patients. MSI-H and TMB-high tumors could benefit from immune-checkpoint inhibitors, now approved for the treatment of MSI-H/deficient mismatch repair metastatic CRC patients. Finally, histone modifiers could serve as a new promising therapeutic target. With confirmatory studies, these results may influence our approach to younger adults with CRC.

IMPLICATIONS FOR PRACTICE

The increasing rate of colorectal cancers (CRC), primarily distal tumors, among young adults poses a global health issue. This study investigates the molecular differences between younger (≤45 years old) and older (≥65) adults with left-sided CRCs. Younger patients more frequently harbor mutations in genes associated with cancer-predisposing syndromes. Higher rates of microsatellite instability-high and tumor mutational burden-high tumors occur in younger patients, who could benefit from immune-checkpoint inhibitors. Finally, histone modifiers are more frequently mutated in younger patients and could serve as a new promising therapeutic target. This study provides new insights into mutations that may guide development of novel tailored therapy in younger CRC patients.

Age-specific impact on the survival of gastric cancer patients with distant metastasis: an analysis of SEER database

The age-specific impact on the survival of gastric cancer patients with distant metastasis is still unclear. In this study, we identified 11, 299 gastric cancer patients with distant metastasis between 2004 and 2013 from Surveillance, Epidemiology, and End Results population-based dataset. Patients were divided into young (≤60) and elderly groups (>60). Kaplan-Meier methods and multivariable Cox regression were used for the analysis of long-term survival outcomes and risk factors. There were significant differences between the two groups in terms of race, primary site, grade, histologic type, surgery, marital status and clinical T stage (P<0.05). The 1- and 3-year cancer specific survival rates were 29.0% and 6.2% in young group and 22.8% and 4.8% in elderly group in both univariate (X²=116.430, P<0.001) and multivariate analysis (P<0.001). Young patients had significantly better 1- and 3-year cancer specific survival than elderly patients in each T stage. Age was further validated as an independent survival factor in all T stages (T1, T2, T3, T4 and T_X, P<0.05). In conclusion, age was an independent prognostic factor for gastric cancer patients with distant metastasis.

Poor prognosis of young patients with colorectal cancer: a retrospective study

PURPOSE

The present study aimed to explore the survival outcomes of patients with colorectal cancer (CRC) aged 35 years and younger.

METHODS

This retrospective cohort study included a total of 995 patients with CRC treated between January 2003 and September 2011. The patients were assorted into the young (aged 18-35 years) and older (aged 36-75 years) groups. The clinical characteristics and survival outcomes of the patients in the young group were compared with those of the patients in the older group for evaluation.

RESULTS

Compared with the older group, a significantly higher number of patients in the young group had right-sided colon cancer (30.9 vs. 19.6%, P = 0.026), high histologic grade tumor (14.7 vs. 6.4%, P = 0.021), and stage III disease (50.0 vs. 35.5%, P = 0.016). In stage III disease, compared with the older group, the patients in the young group had worse survival outcome in terms of 5-year overall survival (OS, P = 0.007), cancer-specific survival (CSS, P = 0.010), and disease-free survival (DFS, P = 0.039). Multivariate analysis revealed that age ≤35 years was an independent risk factor in terms of 5-year OS (hazard ratio [HR] = 1.68; 95% confidence interval [CI]: 1.12-2.54; P = 0.012), CSS (HR = 1.74; 95% CI: 1.15-2.65; P = 0.009), and DFS (HR = 1.58; 95% CI: 1.06-2.35; P = 0.024).

CONCLUSIONS

The young patients with CRC aged 35 years and younger had worse prognosis compared with older patients, especially for stage III disease.

Frequent BRAF mutation in early-onset colorectal cancer in Taiwan: association with distinct clinicopathological and molecular features and poor clinical outcome

BACKGROUND

Occurrence of early-onset colorectal cancer (EOCRC) under the age of 30 is very rare and the molecular characteristics are poorly understood. A low BRAF mutation rate has been noted in several studies of EOCRC from Western countries.

AIMS

To determine the clinicopathological and molecular features of EOCRCs in Taiwan.

METHODS

KRAS/BRAF gene mutation, mismatch repair protein immunohistochemistry, microsatellite instability and CpG island methylation phenotype analyses were examined to determine the molecular characteristics of EOCRC.

RESULTS

Sixty-six patients with EOCRC at our hospital between 2000 and 2012 were studied. BRAF mutation was detected in 11 of the 59 tumours analysed (19%) and the rate was significantly higher than the overall BRAF mutation rate of colorectal cancer in patients older than 30 years (p<0.001). Clinically, 9 of 11 patients with BRAF-mutated tumours presented with advanced-stage diseases and they presented significantly more frequently with stage IV disease than those with BRAF wild-type tumours (p=0.042). Histologically, BRAF mutation was associated with a poorly differentiated histology, a serrated precursor polyp and focal signet ring cell differentiation (p=0.042, 0.008 and 0.008, respectively). None of the BRAF-mutated tumours was mismatch repair protein-deficient and/or microsatellite instability-high. Overall survival of patients with BRAF-mutated tumours was significantly worse than that of patients with BRAF wild-type tumours, despite adjustment for the disease stages and tumour differentiation.

CONCLUSIONS

BRAF mutation was frequent in EOCRCs in Taiwan and was associated with distinct clinicopathological and molecular features.

The impact of oxaliplatin on the gonads: from bedside to the bench

STUDY HYPOTHESIS

What is the impact of oxaliplatin on gonadal function?

STUDY FINDING

Our results in both the clinical and pre-clinical settings indicate that oxaliplatin exerts moderate transient gonadal toxicity.

WHAT IS KNOWN ALREADY

Recent studies have indicated a significant increase in survivorship of colorectal cancer patients of reproductive age, who may then face fertility concerns. The impact of oxaliplatin on gonadal function is yet to be discovered.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

Eleven female (<43 years) and eight male (<45 years) patients recently diagnosed with colorectal cancer, who were candidates for oxaliplatin-based protocol, were enrolled into the study. FSH, estradiol, anti-Müllerian hormone (AMH) and menstrual pattern were measured in female patients, whereas FSH, inhibin-B, testosterone, and steroid-hormone binding globulin were measured in male patients. Hormones were measured at baseline and 6 months post-treatment (last chemotherapy administration) in men and women. In the animal model, pubertal mice were injected with oxaliplatin and sacrificed 1 week, 1 month and 3 months later. Ovarian reserve was estimated by serum AMH measurements. Testicular function was evaluated by serum inhibin-B and sperm evaluation. Gonadal apoptosis (TUNEL), proliferation (Ki-67), repair (PCNA), ovarian reserve (AMH) and testicular reserve (DAZL) were measured by immunohistochemistry.

MAIN RESULTS AND THE ROLE OF CHANCE

In all women, AMH decreased post-treatment, but remained above the detection limit in 9/11 patients (P < 0.05). FSH was elevated, but did not exceed the premenopausal range in 9/11 patients. All patients remain menstruating or resumed menstruation post-treatment. In female mice oxaliplatin induced transient apoptosis at 1-month post-treatment. In men Inhibin-B was slightly reduced post-treatment. In male mice oxaliplatin did not affect spermatozoa concentration, but was associated with transient, moderate reductions of spermatocytes-spermatogonia numbers and spermatozoa motility.

LIMITATIONS, REASONS FOR CAUTION

Future prospective large-scale studies are warranted in order to affirm these outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

Due to high survival rates of colorectal cancer patients of reproductive age that were diagnosed at early stages of the disease, the issue of treatment-induced gonadotoxicity gains significance. Since at the individual level there might be a risk of infertility, a detailed discussion and referral to fertility preservation prior to initiation of treatment is recommended. Nevertheless, oxaliplatin-based protocols appear to be less gonadotoxic than other chemotherapeutic protocols.

LARGE SCALE DATA

None.

STUDY FUNDING AND COMPETING INTERESTS

This study was supported by the Israeli Science Foundation (ISF) grant 13-1816 (I.B.-A.). There is no conflict of interest.