Adjuvant therapy for rectal cancer

Racial comparisons in treatment of rectal adenocarcinoma and survival in the military health system

BACKGROUND

Racial disparities in treatment and outcomes of rectal cancer have been attributed to patients' differential access to care. We aimed to study treatment and outcomes of rectal cancer in the equal access Military Health System (MHS) to better understand potential racial disparities.

METHODS

We accessed the MilCanEpi database to study a cohort of patients aged 18 and older who were diagnosed with rectal adenocarcinoma between 1998 and 2014. Receipt of guideline recommended treatment per tumor stage, cancer recurrence, and all-cause death were compared between non-Hispanic White and Black patients using multivariable regression models with associations expressed as odds (AORs) or hazard ratios (AHRs) and their 95% confidence intervals (CIs).

RESULTS

The study included 171 Black and 845 White patients with rectal adenocarcinoma. Overall, there were no differences in receipt of guideline concordant treatment (AOR = 0.76, 95% CI = 0.45 to 1.29), recurrence (AHR = 1.34, 95% CI = 0.85 to 2.12), or survival (AHR = 1.08, 95% CI = 0.77 to 1.54) for Black patients compared with White patients. However, Black patients younger than 50 years of age at diagnosis (AOR = 0.34, 95% CI = 0.13 to 0.90) or with stage III or IV tumors (AOR = 0.28, 95% CI = 0.12 to 0.64) were less likely to receive guideline recommended treatment than White patients in stratified analysis.

CONCLUSIONS

In the equal access MHS, although there were no overall racial disparities in rectal cancer treatment or clinical outcomes between Black and White patients, disparities among those with early-onset or late-stage rectal cancers were noted. This suggests that factors other than access to care may play a role in the observed disparities and warrants further research.

Clinical benefits of oral capecitabine over intravenous 5-fluorouracyl regimen in case of neoadjuvant chemoradiotherapy followed by surgery for locally advanced rectal cancer

Background: During the last decade, one of the most important treatment options for locally advanced, potencially resectable rectal tumours was neoadjuvant chemoradiotherapy (CRT) followed by surgery. Methods: Effects of the neoadjuvant treatment on surgical outcomes were retrospectively analysed in 185 patients with stage T2-T4 and N0-2, resectable rectal tumour among two patient groups defined by radiosensitizer agents. Group 1 (n = 94) involved radiotherapy (RT) with 50.4 Gy total dose (25 × 1.8 Gy + 3 × 1.8 Gy tumour bed boost), and intravenous 5-fluorouracil (5-FU) (350 mg/m²) with leucovorin (20 mg/m²) on the 1-5 and 21-25 days, while Group 2 (n = 91) RT and orally administrated capecitabine (daily 2 × 825 mg/m²) on RT days. Surgery was carried out after 8-10 weeks. Side effects, perioperative complications, type of surgery, number of removed regional lymph nodes, resection margins and tumour regression grade (TRG) were analysed. Results: More favourable side effects were observed in Group 2. Despite the same rate of diarrhoea (Group 1 vs. Group 2: 54.3% vs. 56.0%), Grade 2-3 diarrhoea ratio was lower (p = 0.0352) after capecitabine (Group 2). Weight loss occurred in 17.0% and 2.2% (p = 0.00067), while nausea and vomiting was described in 38.3% and 15.4% (p = 0.00045) with 5-FU treatment and capecitabine respectively. Anaemia was observed in 33.0% and 22.0% (p = 0.0941). Complete tumour regression occurred in 25.3% after oral- and 13.8% after intravenous treatment (p = 0.049). Ratio of sphincter preservation was higher with laparoscopy than open surgery (72.3% vs. 39.7%) (p = 0.00001). Conclusion: The study confirms advantages of neoadjuvant chemoradiotherapy with oral capecitabine for rectal tumours, such as more favourable side effect profile and overall clinical outcome, with increased rate of complete tumour regression.

Preoperative heat shock protein 47 levels identify colorectal cancer patients with lymph node metastasis and poor prognosis

Accumulating evidence suggests that overexpression of heat shock protein 47 (HSP47) increases cancer progression, and that HSP47 level in the tumor-associated stroma may serve as a diagnostic marker in various cancers. The present study aimed to evaluate whether HSP47 gene expression in colorectal cancer (CRC) tissues could be used to identify lymph node (LN) metastasis status preoperatively in patients with CRC. To do so, HSP47 gene expression was determined and its association with the clinicopathological characteristics of patients with CRC was analyzed. A total of 139 surgical specimens from patients with CRC and 36 patients with benign colonic disease undergoing surgery at Mie University Hospital were analyzed. HSP47 gene expression was determined by reverse transcription quantitative PCR using Power SYBR Green PCR methods. Expression level of HSP47 was significantly higher in CRC tissues compared with normal tissue from patients with benign colonic disease. Furthermore, high HSP47 expression was significantly associated with tumor progression, including high T stage, lymph node metastasis and venous invasion, and high TNM stage. High HSP47 expression may therefore serve as a novel predictive biomarker for determining patients with CRC and LN metastasis. According to Kaplan-Meier analysis, patients with high HSP47 expression level had significantly poorer overall survival than those with low HSP47 expression level. Furthermore, multivariate analyses identified HSP47 expression as an independent predictive marker for LN metastasis and poor overall survival in patients with CRC. In summary, the present study demonstrated that HSP47 expression may be considered as a novel biomarker for predicting LN metastasis status and prognosis in patients with CRC.

Association Between Incomplete Neoadjuvant Radiotherapy and Survival for Patients With Locally Advanced Rectal Cancer

Importance

Failing to complete chemotherapy adversely affects survival in patients with colorectal cancer. However, the effect of incomplete delivery of neoadjuvant radiotherapy is unclear.

Objective

To determine whether incomplete radiotherapy delivery is associated with worse clinical outcomes and survival.

Design, Setting, and Participants

Data on 17 600 patients with stage II to III rectal adenocarcinoma from the 2006-2012 National Cancer Database who received neoadjuvant chemoradiotherapy followed by surgical resection were included. Multivariable regression methods were used to compare resection margin positivity, permanent colostomy rate, 30-day readmission, 90-day mortality, and overall survival between patients who received complete (45.0-50.4 Gy) and incomplete (<45.0 Gy) doses of radiation as preoperative therapy.

Main Outcomes and Measures

The primary outcome measure was overall survival; short-term perioperative and oncologic outcomes encompassing margin positivity, permanent ostomy rate, postoperative readmission, and postoperative mortality were also assessed.

Results

Among 17 600 patients included, 10 862 were men, with an overall median age of 59 years (range, 51-68 years). Of these, 874 patients (5.0%) received incomplete doses of neoadjuvant radiation. The median radiation dose received among those who did not achieve complete dosing was 34.2 Gy (interquartile range, 19.8-40.0 Gy). Female sex (adjusted odds ratio [OR] 0.69; 95% CI, 0.59-0.81; P < .001) and receiving radiotherapy at a different hospital than the one where surgery was performed (OR, 0.72; 95% CI, 0.62-0.85; P < .001) were independent predictors of failing to achieve complete dosing; private insurance status was predictive of completing radiotherapy (OR, 1.60; 95% CI, 1.16-2.21; P = .004). At 5-year follow-up, overall survival was improved among patients who received a complete course of radiotherapy (3086 [estimated survival probability, 73.2%] vs 133 [63.0%]; P < .001). After adjustment for demographic, clinical, and tumor characteristics, patients receiving a complete vs incomplete radiation dose had a similar resection margin positivity (OR, 0.99; 95% CI, 0.72-1.35; P = .92), permanent colostomy rate (OR, 0.96; 95% CI, 0.70-1.32; P = .81), 30-day readmission rate (OR, 0.92; 95% CI, 0.67-1.27; P = .62), and 90-day mortality (OR, 0.72; 95% CI, 0.33-1.54; P = .41). However, a complete radiation dose had a significantly lower risk of long-term mortality (adjusted hazard ratio, 0.70; 95% CI, 0.59-0.84; P < .001).

Conclusions and Relevance

Achieving a target radiation dose of 45.0 to 50.4 Gy is associated with a survival benefit in patients with locally advanced rectal cancer. Aligning all aspects of multimodal oncology care may increase the probability of completing neoadjuvant therapy.

Is Chemotherapy or Radiation Therapy in Addition to Surgery Beneficial for Locally Advanced Rectal Cancer in the Elderly? A National Cancer Data Base (NCDB) Study

INTRODUCTION

Current National Comprehensive Cancer Network guidelines for Stages II and III rectal cancer recommend neoadjuvant chemoradiation followed by curative intent surgery and adjuvant chemotherapy. It is unclear whether therapies in addition to surgery are truly beneficial in elderly patients. Our aim was to compare the survival of patients over 80 with Stages II and III rectal cancer undergoing curative intent surgery with or without additional therapy.

MATERIALS AND METHODS

The National Cancer Data Base (NCDB 2006-2011) was queried for patients over 80 with Stages II and III rectal cancer. The primary outcome was overall survival. Patients were stratified based upon therapy group. Univariate group comparisons were made. Unadjusted Kaplan-Meier and multivariable Cox proportional hazards modeling survival analyses were performed.

RESULTS

The query yielded 3098 patients over 80 with Stage II (N = 1566) or Stage III (N = 1532) disease. Approximately, half of the patients received surgery only. Kaplan-Meier analysis showed improved survival for patients receiving neoadjuvant and/or adjuvant therapy in addition to surgery, but there was no significant difference between those that received guideline concordant care (GCC), neoadjuvant chemoradiation only, or post-operative chemotherapy only. Cox proportional hazard modeling identified age >90 and margin positivity as independent risk factors for decreased overall survival.

CONCLUSION

Analysis of NCDB data for Stages II and III rectal cancer in patients over 80 shows a survival benefit of adjuvant and/or neoadjuvant therapy over surgery alone. There does not appear to be a difference in survival between patients who received neoadjuvant chemoradiation, post-resection adjuvant chemotherapy, or GCC.

A Predictive Genetic Signature for Response to Fluoropyrimidine-Based Neoadjuvant Chemoradiation in Clinical Stage II and III Rectal Cancer

PURPOSE

Pre-operative chemoradiation (CRT) is currently the standard of care for patients with clinical stage II and III rectal cancer but only about 45% of patients achieve tumor downstaging and <20% of patients achieve a pathologic complete response. Better methods to stratify patients according to potential neoadjuvant treatment response are needed. We used microarray analysis to identify a genetic signature that correlates with a pathological complete response (pCR) to neoadjuvant CRT. We performed a gene network analysis to identify potential signaling pathways involved in determining response to neoadjuvant treatment.

PATIENTS AND METHODS

We identified 31 T3-4 N0-1 rectal cancer patients who were treated with neoadjuvant fluorouracil-based CRT. Eight patients were identified to have achieved a pCR to treatment while 23 patients did not. mRNA expression was analyzed using cDNA microarrays. The correlation between mRNA expression and pCR from pre-treatment tumor biopsies was determined. Gene network analysis was performed for the genes represented by the predictive signature.

RESULTS

A genetic signature represented by expression levels of the three genes EHBP1, STAT1, and GAPDH was found to correlate with a pCR to neoadjuvant treatment. The difference in expression levels between patients who achieved a pCR and those who did not was greatest for EHBP1. Gene network analysis showed that the three genes can be connected by the gene ubiquitin C (UBC).

CONCLUSION

This study identifies a 3-gene signature expressed in pre-treatment tumor biopsies that correlates with a pCR to neoadjuvant CRT in patients with clinical stage II and III rectal cancer. These three genes can be connected by the gene UBC, suggesting that ubiquitination is a molecular mechanism involved in determining response to treatment. Validating this genetic signature in a larger number of patients is proposed.