Is it safe to omit neoadjuvant chemo-radiation in mucinous rectal carcinoma?

Incomplete Resection Is Twice as Likely in Locally Advanced Mucinous Compared to Nonmucinous Rectal Adenocarcinoma: A National Propensity-Matched Analysis

BACKGROUND AND OBJECTIVES

Rectal mucinous adenocarcinoma (MA) has poor response to neoadjuvant chemoradiation (NCR) and higher involved radial surgical margin rates than nonmucinous rectal adenocarcinoma (NMA).

METHODS

The National Cancer Database (2010-2018) was queried for adult patients with clinical stage II and III rectal cancer. Patients with MA and NMA treated with NCR and total mesorectal excision (TME) were identified. We sought to evaluate differences in pathologic downstaging and completeness of resection between MA and NMA rectal adenocarcinoma.

RESULTS

We identified 13 294 patients, 12 655 (95.2%) NMA and 639 (4.8%) MA. After 3:1 propensity score matching for pathologic outcomes, 1707 NMA and 569 MA patients were included. MA patients had more involved distal (2.1% vs. 1.1%, p = 0.047) and radial (29% vs. 15%, p < 0.001) margins, and less pathologic downstaging (49% vs. 55%, p = 0.015). Among MA patients, minimally invasive resection had higher distal (2.1% vs. 1.4%, p = 0.65) and radial margin involvement (35% vs. 26%, p = 0.09) compared to open resection. Incomplete resection rates were similar between low anterior and abdominoperineal resection.

CONCLUSIONS

TME of locally advanced rectal MA treated with NCR resulted in nearly double the involved radial surgical margins compared to NMA. Operative approach should be carefully considered. Extended or extra-mesorectal resection may reduce the risk of incomplete resection.

Does stage III rectal mucinous adenocarcinoma benefit from neoadjuvant chemoradiation?

BACKGROUND

This study aimed to compare clinical outcomes of patients with clinical stage III mucinous rectal adenocarcinoma (M) and non-mucinous rectal adenocarcinoma (NM) and evaluate the effectiveness of neoadjuvant chemoradiation. It was hypothesized that patients with M would fare worse with neoadjuvant chemoradiation than those with NM and that patients with M and NM not receiving chemoradiation would have similar outcomes. Moreover, it was hypothesized that patients with M would have similar outcomes regardless of chemoradiation.

METHODS

This study compares eligible patients distributed in three cohorts: (cohort 1) M versus NM, including only patients treated with neoadjuvant chemoradiation; (cohort 2) M versus NM, including only patients treated without neoadjuvant chemoradiation; and (cohort 3) only M patients treated with versus without neoadjuvant chemoradiation.

RESULTS

We identified 515 patients with an average age of 58.8 (SD 12.4) years, and 30% were female. Fifty-seven (11.1%) patients had M and 458 (88.9%) had NM. Neoadjuvant chemoradiation was administered to 382 (74%) patients, of whom 41 (10.7%) were M and 341 (89.3%) NM. In cohort 1, patients with M had advanced pathological staging (stage 3: M 68% vs. NM 42%; p < 0.001), worse pathological differentiation (poor: M, 37% vs. NM, 11%; p = 0.001), more involved lymph nodes (M 0 [0;7] vs. NM 0 [0;1]; p < 0.001) and a higher rate of local recurrence (M 22% vs. 3%; p < 0.001). Patients with M demonstrated worse 7-year cancer-specific (p = 0.007) and overall survival (p = 0.01). There were no significant differences in cohort 2 and 3.

CONCLUSION

Patients with clinical stage III mucinous adenocarcinomas may not benefit as much from standard neoadjuvant chemoradiation as their non-mucinous counterparts do.

A Propensity Score-Matched Analysis of the Impact of Neoadjuvant Radiation Therapy on the Outcomes of Stage II and III Mucinous Rectal Carcinoma

BACKGROUND

Patients with mucinous rectal carcinoma tend to present in advanced stage with a poor prognosis.

OBJECTIVE

This study aimed to assess the effect of neoadjuvant radiation therapy on outcomes of patients with stage II and III mucinous rectal carcinomas using data from the National Cancer Database.

DESIGN

Retrospective analysis of prospective national databases.

SETTING

National Cancer Database between 2004 and 2019.

PATIENTS

Patients with mucinous rectal carcinoma.

INTERVENTION

Patients who did or did not receive neoadjuvant radiation therapy were matched using the nearest-neighbor propensity score method for age, clinical stage, neoadjuvant systemic treatment, and surgery type.

MAIN OUTCOME MEASURES

Main outcomes of the study were numbers of total harvested and positive lymph nodes, disease downstaging after neoadjuvant radiation, and overall survival. Other outcomes were hospital stay, short-term mortality, and readmission.

RESULTS

A total of 3062 patients (63.5% men) with stage II and III mucinous rectal carcinoma were included, 2378 of whom (77.7%) received neoadjuvant radiation therapy. After 2:1 propensity score matching, 143 patients in the no neoadjuvant group were matched to 286 patients in the neoadjuvant group. The mean overall survival was similar (77.3 vs 81.9 months; p = 0.316). Patients who received neoadjuvant radiation therapy were less often diagnosed with pathologic T3 and 4 disease (72.3% vs 81.3%, p = 0.013) and more often had pathologic stage 0 and 1 disease (16.4% vs 11.2%, p = 0.001), yet with a higher stage III disease (49.7% vs 37.1%, p = 0.001). Neoadjuvant radiation was associated with fewer examined lymph nodes (median: 14 vs 16, p = 0.036) and positive lymph nodes than patients who did not receive neoadjuvant radiation. Short-term mortality, readmission, hospital stay, and positive surgical margins were similar.

LIMITATIONS

Retrospective study and missing data on disease recurrence.

CONCLUSIONS

Patients with mucinous rectal carcinoma who received neoadjuvant radiation therapy had marginal downstaging of disease, fewer examined and fewer positive lymph nodes, and similar overall survival to patients who did not receive neoadjuvant radiation. See Video Abstract .

UN ANLISIS EMPAREJADO POR PUNTUACIN DE PROPENSIN DEL IMPACTO DE LA RADIOTERAPIA NEOADYUVANTE EN LOS RESULTADOS DEL CARCINOMA MUCINOSO DE RECTO EN ESTADIO IIIII

ANTECEDENTES:Los pacientes con carcinoma mucinoso de recto tienden a presentarse en estadio avanzado con mal pronóstico.OBJETIVO:Este estudio tuvo como objetivo evaluar el efecto de la radioterapia neoadyuvante en los resultados de pacientes con carcinomas mucinosos de recto en estadio II-III utilizando datos de la Base de Datos Nacional del Cáncer.DISEÑO:Análisis retrospectivo de bases de datos nacionales prospectivas.PACIENTES:Pacientes con carcinoma mucinoso de recto.AJUSTE:Base de datos nacional sobre el cáncer entre 2004 y 2019.INTERVENCIÓN:Los pacientes que recibieron o no radioterapia neoadyuvante fueron emparejados utilizando el método de puntuación de propensión del vecino más cercano por edad, estadio clínico, tratamiento sistémico neoadyuvante y tipo de cirugía.PRINCIPALES MEDIDAS DE VALORACIÓN:Los principales resultados del estudio fueron el número total de ganglios linfáticos extraídos y positivos, la reducción del estadio de la enfermedad después de la radiación neoadyuvante y la supervivencia general. Otros resultados fueron la estancia hospitalaria, la mortalidad a corto plazo y el reingreso.RESULTADOS:Se incluyeron 3.062 pacientes (63,5% hombres) con carcinoma mucinoso de recto estadio II-III, de los cuales 2.378 (77,7%) recibieron radioterapia neoadyuvante. Después de un emparejamiento por puntuación de propensión 2:1, 143 pacientes del grupo sin neoadyuvancia fueron emparejados con 286 del grupo neoadyuvante. La supervivencia global media fue similar (77,3 vs 81,9 meses; p = 0,316). A los pacientes que recibieron radiación neoadyuvante se les diagnosticó con menos frecuencia enfermedad pT3-4 (72,3% frente a 81,3%, p = 0,013) y con mayor frecuencia tenían enfermedad en estadio patológico 0-1 (16,4% frente a 11,2%, p = 0,001), aunque con una enfermedad en estadio III superior (49,7% vs 37,1%, p = 0,001). La radiación neoadyuvante se asoció con menos ganglios linfáticos examinados (mediana: 14 frente a 16, p = 0,036) y ganglios linfáticos positivos que los pacientes que no recibieron radiación neoadyuvante. La mortalidad a corto plazo, el reingreso, la estancia hospitalaria y los márgenes quirúrgicos positivos fueron similares.LIMITACIONES:Estudio retrospectivo y datos faltantes sobre recurrencia de la enfermedad.CONCLUSIONES:Los pacientes con carcinoma mucinoso de recto que recibieron radioterapia neoadyuvante tuvieron una reducción marginal de la enfermedad, menos ganglios linfáticos examinados y positivos, y una supervivencia general similar a la de los pacientes que no recibieron radiación neoadyuvante. (Traducción- Dr Ingrid Melo ).

Long-term effect of neoadjuvant radiotherapy in patients with locally advanced rectal mucinous adenocarcinoma: a population-based study of 1514 patients

Rectal mucinous adenocarcinoma (RMAC) is a rare and aggressive form of rectal cancer. The effectiveness of neoadjuvant radiotherapy (NRT) for RMAC has not been well studied, and the survival benefit remains controversial. The purpose of this work was to determine the prognostic role of NRT in patients with RMAC by propensity-score matching (PSM). A retrospective cohort study using the Surveillance, Epidemiology, and End Results from 2004 to 2015 was performed. In the multivariate analysis before PSM, NRT provided better OS (HR 0.61, 95% CI 0.52-0.71, p < 0.001) and CSS (HR 0.68, 95% CI 0.56-0.82, p < 0.001). Multivariate analysis after PSM (n = 844) confirmed that patients receiving NRT survived longer than those without NRT (OS: HR 0.60, 95% CI 0.50-0.78, p < 0.001 and CSS: HR 0.68, 95% CI 0.54-0.84, p < 0.001). Subgroup analysis indicated that NRT had significantly improved OS and CSS in stage II RMAC and OS in stage III RMAC after adjusting for various confounding factors.

Trends in the Characteristics, Treatment, and Outcomes of Rectal Adenocarcinoma in the US From 2004 to 2019: A National Cancer Database Analysis

IMPORTANCE

Rectal cancer management has significantly evolved over the last 2 decades.

OBJECTIVE

This study aimed to evaluate trends in the characteristics, treatment, and outcomes of rectal adenocarcinoma across 16 years.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, observational case series study used data from the National Cancer Database (NCDB) to evaluate patients diagnosed with rectal adenocarcinoma from 2004 through 2019. Data analysis was performed from March to May 2022.

EXPOSURES

Trends in the treatment and outcomes of rectal adenocarcinoma in the US between 2004 and 2019 were explored. This period was subdivided into 4 equal periods: 2004-2007, 2008-2011, 2012-2015, and 2016-2019.

MAIN OUTCOMES AND MEASURES

Patient and tumor characteristics, treatments, short-term outcomes, and overall survival.

RESULTS

A total of 318 548 patients diagnosed with rectal adenocarcinoma were included in the analysis, 191 369 (60.1%) of whom were males and 127 179 (39.9%%) were females. The mean (SD) age of the patients was 63.5 (13.4) years, and 46 824 patients (14.8%) were younger than 50 years. Among the patients, 10 859 (3.4%) were of Asian race and ethnicity, 28 464 (8.9%) were Black, and 271 236 (85.1%) were White. The percentage of patients younger than 50 years who were diagnosed with rectal cancer increased by 1.5%, from 13.9% in period 1 to 15.4% in period 4. Patients in the last period (2016-2019) presented more often with stages III (36.2% vs 30.2% vs 25.0% vs 23.4%; P < .001) and IV (21.5% vs 19.3% vs 18.1% vs 18.6%; P < .001) disease compared with those in the remaining 3 periods. The use of chemotherapy (36.8% vs 48.1% vs 49.1% vs 47.0%; P < .001) and immunotherapy (0.4% vs 0.2% vs 3.5% vs 6.5%; P < .001) significantly increased across the 4 periods. Although neoadjuvant radiotherapy was used more often across the periods studied (28.6% in period 1 to 34.3% in period 4), the use of adjuvant radiotherapy was reduced by half (12.9% to 6.0%). The median (IQR) time from diagnosis to definitive surgery increased from 95 (15-126) days in period 1 to 128 (47-158) days in period 4. The rate of use of open surgery decreased by half (60.1% in period 2 to 30.1% in period 4), and the use of robotic surgery significantly increased (5.2% in period 2 to 28.4% in period 4). The conversion rate was significantly reduced (11.2% in period 2 to 7.3% in period 4) and the median (IQR) hospital stay decreased by 2 days, from 6 (3-9) days to 4 (2-7) days. The median (IQR) overall survival significantly increased across the periods (from 83.1 months [95% CI, 81.8-84.6 months] in period 1 to 92.1 months [95% CI, 90.2-93.6 months] in period 3; P < .001).

CONCLUSION AND RELEVANCE

The findings of this case series study suggest a treatment trend of increased use of chemotherapy, immunotherapy, sphincter-saving surgery, and minimally invasive surgery. In addition, the time between diagnosis and definitive surgery increased by a median of 33 days. This treatment trend was associated with a significant improvement in the overall survival, reduction in the conversion rate by 3.9%, and a 2-day shorter hospital stay. These findings have major clinical relevance to the management of rectal cancer. The improvements seen in short-term outcomes and survival of patients diagnosed with rectal cancer can probably be attributed to the treatment trends observed. Continued improvement in outcomes warrant further updates in treatments.

Rectal Cancer in Patients with Hereditary Nonpolyposis Colorectal Cancer Compared with Sporadic Cases: Response to Neoadjuvant Chemoradiation and Local Recurrence

BACKGROUND

This study aimed to assess the effect of neoadjuvant chemoradiation (nCXRT) on tumor regression and oncologic outcome of middle and low rectal cancer in patients of hereditary nonpolyposis colorectal cancer (HNPCC) compared to sporadic cases.

STUDY DESIGN

This was a retrospective cohort study that compared the outcomes of patients with HNPCC presenting with middle or low rectal cancer indicated for nCXRT vs patients with sporadic rectal cancer. All patients received long-course nCXRT followed by total mesorectal excision. Primary outcome was pathologic tumor regression grade (TRG) assessed after resection. Secondary outcomes included disease-free survival and overall survival.

RESULTS

Fifty-eight patients with HNPCC (24 female) were included in the study matched with 58 patients with sporadic rectal cancer (out of 166 using propensity score matching). Patients with HNPCC and sporadic rectal cancer were matched regarding tumor pathology TNM stage and lymphovascular invasion. In the HNPCC group, 36 patients (62%) had tumor regression (TRG3 = 6 (10.3%); TRG2 = 12 (20.6%); TRG1 = 18 (31%)) compared to 52 patients (92%) who had tumor regression in the control group (TRG4 = 9; TRG3 = 15; TRG2 = 18; TRG1 = 10) (p < 0.0007). After a median follow-up of 48 months, survival analysis revealed higher local recurrence and lower overall survival in patients with HNPCC compared to patients with sporadic rectal cancer.

CONCLUSIONS

Rectal cancer in patients with HNPCC showed poorer response to nCXRT and was followed by higher local recurrence and lower overall survival than patients with sporadic rectal cancer. Tumor regression was detected in <65% of patients with HNPCC compared to >90% of patients with sporadic rectal cancer, and none of patients with HNPCC had a complete response.

Effects of Neoadjuvant Radiotherapy on Postoperative Complications in Rectal Cancer: A Meta-Analysis

Objective

Neoadjuvant radiotherapy (nRT) is an important treatment approach for rectal cancer. The relationship, however, between nRT and postoperative complications is still controversial. Here, we conducted a meta-analysis to evaluate such concerns.

Methods

The electronic literature from 1983 to 2021 was searched in PubMed, Embase, and Web of Science. Postoperative complications after nRT were included in the meta-analysis. The pooled odds ratio (OR) was calculated by the random-effects model. Statistical analysis was conducted by Review Manager 5.3 and STATA 14.

Results

A total of 23,723 patients from 49 studies were included in the meta-analysis. The pooled results showed that nRT increased the risk of anastomotic leakage (AL) compared to upfront surgery (OR = 1.23; 95% CI, 1.07-1.41; p=0.004). Subgroup analysis suggested that both long-course (OR = 1.20, 95% CI 1.03-1.40; p=0.02) and short-course radiotherapy (OR = 1.25, 95% CI, 1.02-1.53; p=0.04) increased the incidence of AL. In addition, nRT was the main risk factor for wound infection and pelvic abscess. The pooled data in randomized controlled trials, however, indicated that nRT was not associated with AL (OR = 1.01; 95% CI 0.82-1.26; p=0.91).

Conclusions

nRT may increase the risk of AL, wound infection, and pelvic abscess compared to upfront surgery among patients with rectal cancer.

Patients with early-onset rectal cancer aged 40 year or less have similar oncologic outcomes to older patients despite presenting in more advanced stage; A retrospective cohort study

BACKGROUND

Early-onset colon and rectal cancer has increased in alarming rates. The present study reviewed the characteristics and outcome of early-onset rectal cancer in patients aged ≤40 years.

METHODS

This was a retrospective cohort study on rectal cancer patients who were treated in a tertiary center in the Middle East. Baseline characteristics and outcomes of patients ≤40 years were compared with patients >40 years. Main outcome measures were patients' and tumor characteristics, local recurrence, distance metastasis, overall survival (OS), and disease-free survival (DFS).

RESULTS

Among 244 patients with rectal cancer, 81 (33.2%) aged 40 years or less. 56.8% of patients ≤40 years and 49.7% of patients >40 years presented with stage III/IV disease (p = 0.36). Local recurrence and distant metastasis were detected in 10.3% and 13.2% of patients ≤40 years and in 16.9% and 13.9% of patients >40 years (p = 0.29 and 0.88). The 3-year OS and DFS rates of patients ≤40 years were 75% and 80.9% versus 74.2% and 76.5% in patients >40 years (p = 0.9 and 0.59). Patients ≤40 years presented with ulcerative carcinoma (38.3% vs 21.5%, p = 0.01) and signet-ring carcinoma (12.3% vs 2.5%, p = 0.008) more than patients > 40 years.

CONCLUSION

Early-onset rectal cancer accounted for one-third of all patients presenting with rectal cancer. Patients younger than 40 years had higher incidence of mucinous and signet-ring rectal carcinoma, and presented more with advanced stage. The age of patients did not have a significant impact on the oncologic outcome of rectal cancer.

Radiomics analysis of multicenter CT images for discriminating mucinous adenocarcinoma from nomucinous adenocarcinoma in rectal cancer and comparison with conventional CT values

OBJECTIVE

To investigate the value of CT-based radiomics signature for preoperatively discriminating mucinous adenocarcinoma (MA) from nomucinous adenocarcinoma (NMA) in rectal cancer and compare with conventional CT values.

METHOD

A total of 225 patients with histologically confirmed MA or NMA of rectal cancer were retrospectively enrolled. Radiomics features were computed from the entire tumor volume segmented from the post-contrast phase CT images. The maximum relevance and minimum redundancy (mRMR) and LASSO regression model were performed to select the best preforming features and build the radiomics models using a training cohort of 155 cases. Then, predictive performance of the models was validated using a validation cohort of 70 cases and receiver operating characteristics (ROC) analysis method. Meanwhile, CT values in post- and pre-contrast phase, as well as their difference (D-values) of tumors in two cohorts were measured by two radiologists. ROC curves were also calculated to assess diagnostic efficacies.

RESULTS

One hundred and sixty-three patients were confirmed by pathology as NMA and 62 cases were MA. The radiomics signature comprised 19 selected features and showed good discrimination performance in both the training and validation cohorts. The areas under ROC curves (AUC) are 0.93 (95% confidence interval [CI]: 0.89-0.98) in training cohort and 0.93 (95% CI: 0.87-0.99) in validation cohort, respectively. Three sets of CT values of MA in pre- and post-contrast phase, and their difference (D-value) (31±7.0, 51±12.6 and 20±9.3, respectively) were lower than those of NMA (37±5.6, 69±13.3 and 32±11.7, respectively). Comparing to the radiomics signature, using three sets of conventional CT values yielded relatively low diagnostic performance with AUC of 0.84 (95% CI: 0.78-0.88), 0.75 (95% CI: 0.69-0.81) and 0.78 (95% CI: 0.72-0.83), respectively.

CONCLUSION

This study demonstrated that CT radiomics features could be utilized as a noninvasive biomarker to identify MA patients from NMA of rectal cancer preoperatively, which is more accurate than using the conventional CT values.

Predictors for local recurrence and distant metastasis of mucinous colorectal adenocarcinoma

BACKGROUND

Mucinous adenocarcinoma (MA) is a unique subtype of colorectal carcinoma. Although some investigators considered MA a predictor for poor prognosis, predictors for poor clinical outcome of MA were not elucidated. The present study aimed to investigate the predictors for local recurrence and distant metastasis of MA.

METHODS

This was a retrospective review of patients with MA who underwent operation with curative intent. Variables included patient and tumor characteristics, TNM stage, investigations, details of surgery, and postoperative outcomes, including local recurrence and distant metastasis. Univariate and multivariate regression analyses were performed to determine the risk factors for local and systemic disease recurrence.

RESULTS

A total of 106 patients (83 male) of a mean age of 51.5 years were included; 62% of patients had colonic tumors, and 38% had rectal tumors; 77% and 58% of colonic and rectal cancers, respectively, were T3-T4 tumors. There were no lymph node metastases in 61% of colonic tumors and 55% of rectal tumors. Local recurrence occurred in 15 patients (14%) and distant metastasis in 9 (9%). Predictors for local recurrence were age (odds ratio [OR]: 1.04; P = .04), female sex (OR: 4.5; P = .01), rectal tumors (OR: 3.73; P = .02), and T4 tumors (OR: 10.9; P = 0.03). Predictors for distant metastasis were age (OR: 1.1; P = .016), local recurrence (OR: 24.28; P < .0001), and T4 tumors (OR: 19.3; P = .049).

CONCLUSION

Patients' age, female sex, and T4 tumors were significant predictors for local recurrence and distant metastasis. Rectal tumors had a greater likelihood for regional recurrence than colonic tumors. Local recurrence was an independent risk factor for distant metastasis.

Adjuvant radiotherapy improves cause specific survival in stage II, not stage III mucinous carcinoma of the rectum

Background

The effect of adjuvant radiotherapy on the survival outcomes of patients with mucinous rectal cancer remains unclear. This study evaluated the 5-year cause specific survival (CSS) of patients with mucinous rectal cancer after surgery to determine whether adjuvant radiotherapy conferred a survival benefit.

Methods

An analysis of the Surveillance, Epidemiology, and End Results (SEER)-registered database was conducted of patients presenting with mucinous rectal cancer between 2004 and 2011. The primary endpoint was 5-year CSS; univariate and multivariate analyses were performed using Cox proportional hazards regression models.

Results

A total of 574 patients were included for analysis with 248 patients in postoperative radiotherapy group and 326 patients in surgery alone group. Preliminary analysis demonstrated that adjuvant radiotherapy was not associated with CSS (χ² = 0.560, P = 0.454). Subgroup analysis indicated that postoperative radiotherapy group had survival advantage in stage II rectal cancer (93.3% vs. 76.6%, χ² = 4.654, P = 0.031), but not in stage III rectal cancer (67.5% vs. 64.7%, χ² = 0.186, P = 0.666). Multivariate analysis demonstrated that postoperative radiotherapy group had a reduced risk of death on survival (HR 0.346; 95%CI 0.129-0.927, P = 0.035)

Conclusion

Postoperative radiotherapy is an independent factor for improvement in CSS in patients with stage II rectal mucinous adenocarcinoma, and it should be routinely recommended in these patients. But for stage III patients, considering the losing of CSS advantage and potential radiotherapy toxicity, postoperative radiotherapy should be recommended with great caution.