Adjuvant treatment for resected rectal cancer: impact of standard and intensified postoperative chemotherapy on disease-free survival in patients undergoing preoperative chemoradiation-a propensity score-matched analysis of an observational database

The benefits of adjuvant chemotherapy are associated with the kind of neoadjuvant therapy in stage ypI rectal cancer: evidence based on population analysis

PURPOSE

The oncological role of adjuvant chemotherapy (ACT) remains debated in locally advanced rectal cancer (RC) after neoadjuvant therapy (NAT), especially ypI RC. In this study, we used population-based data to evaluate the benefits of ACT in stage ypI RC after NAT and surgery. Moreover, we tried to differentiate what kind of NAT (radiotherapy alone or chemoradiotherapy) was administered because this may affect the further efficacy of ACT.

METHODS

All patients with stage ypI primary rectal malignancy were diagnosed in the SEER database between 2004 and 2017. The Kaplan-Meier method was applied to estimate the effects of ACT in survival analysis. Cox regression was performed to calculate the hazard ratio (HR) and the prognosis factors of survival. Propensity score matching (PSM) was used to balance the parameters between therapy groups.

RESULTS

The overall cohort's median follow-up time was 105 months. For 5-year OS and CSS, there were no significant differences between the ACT ( +) and ACT (-) groups (p = 0.105; p = 0.788). However, subgroup analyses according to the kind of NAT found that ACT improved overall survival (OS) and cancer-specific survival (CSS) in patients who received neoadjuvant radiotherapy (nRT) (p < 0.001, p = 0.015). Among patients who received neoadjuvant chemoradiotherapy (nCRT), no significant survival benefits were found between the ACT ( +) and ACT (-) groups (p = 0.526, p = 0.288).

CONCLUSION

Our population-based cohort study suggested that the efficacy of ACT was associated with the kind of NAT. The ACT provides survival benefits in stage ypI RC for patients who received nRT. However, among patients who received nCRT, ACT did not improve long-term survival.

Adjuvant chemotherapy and survival outcomes in rectal cancer patients with good response (ypT0-2N0) after neoadjuvant chemoradiotherapy and surgery: A retrospective nationwide analysis

Background

For rectal cancer, it remains unclear how to incorporate tumor response to neoadjuvant chemoradiotherapy (nCRT) when deciding whether to give adjuvant chemotherapy. In this study, we aim to determinate the survival benefit of adjuvant chemotherapy for rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Methods

The study cohort included 720 rectal cancer patients who had good response (ypT0-2N0) after nCRT and surgery, who did or did not receive adjuvant chemotherapy between January 2007 and December 2017, from the Taiwan Cancer Registry and National Health Insurance Research database. The Kaplan-Meier method, log-rank tests, and Cox regression analysis were performed to investigate the effect of adjuvant chemotherapy on 5-year overall survival (OS) and disease-free survival (DFS).

Results

Of 720 patients, 368 (51.1%) received adjuvant chemotherapy and 352 (48.9%) did not. Patients who received adjuvant chemotherapy were more likely to be female, younger (≤ 65), with advanced clinical T (3-4)/N (1-2) classification and ypT2 classification. No significant difference in 5-year OS (p=0.681) or DFS (p=0.942) were observed by receipt of adjuvant chemotherapy or not. Multivariable analysis revealed adjuvant chemotherapy was not associated with better OS (adjusted hazard ratio [aHR], 1.03; 95% Confidence Interval [CI], 0.88-1.21) or DFS (aHR, 1.05; 95% CI, 0.89-1.24). Stratified analysis for OS and DFS found no significant protective effect in the use of adjuvant chemotherapy, even for those with advanced clinical T or N classification.

Conclusion

Adjuvant chemotherapy may be omitted in rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Postoperative Adjuvant Treatment Strategy for Locally Advanced Rectal Cancer after Neoadjuvant Treatment

Background

Neoadjuvant (chemo) radiotherapy is used as a standard treatment for locally advanced rectal cancer (LARC), but there is no general consensus on either the efficacy of postoperative adjuvant chemotherapy in patients with LARC after neoadjuvant treatment and surgery, or whether the addition of oxaliplatin to adjuvant chemotherapy provides survival benefits.

Methods

We performed a meta-analysis of data from the PubMed and Embase databases. We included patients with LARC who received neoadjuvant (chemo) radiotherapy and curative surgery. Overall survival (OS), disease-free survival (DFS), toxicity, and compliance were analyzed in the oxaliplatin/fluorouracil- (OX/FU-) based group compared with the FU-based group, and in the chemotherapy group compared with the observation group.

Results

Twenty studies were included in the analysis. Our results indicated that adjuvant chemotherapy prolonged OS (hazard ratio [HR] = 0.78, 95%CI = 0.67–0.91) in patients with LARC treated with neoadjuvant (chemo) radiotherapy and surgery compared with those in the observation group. Subgroup analysis showed the same results in both the ypStage II and ypStage III groups. Compared with those in the observation group, patients in the chemotherapy group also showed an increase in DFS (HR = 0.75, 95%CI = 0.60–0.93). No significant increase was observed in OS (HR = 1.04, 95%CI = 0.87–1.24) or DFS (HR = 0.98, 95%CI = 0.76–1.27) when oxaliplatin was added to FU-based adjuvant chemotherapy, as compared with the FU-based treatment, and subgroup analysis also indicated no survival benefits in the clinical stage II, clinical stage III, ypStage II, and ypStage III groups.

Conclusions

For patients with LARC who have already received neoadjuvant (chemo) radiotherapy and curative surgery, adjuvant chemotherapy improves OS over that in the observation group. Adding oxaliplatin to FU-based adjuvant chemotherapy does not confer survival benefits beyond those from FU-based adjuvant chemotherapy.

Downstaged ypT0-2N0 rectal cancer after neoadjuvant chemoradiation therapy may not need adjuvant chemotherapy: a retrospective cohort study

PURPOSE

Current guidelines suggest that adjuvant chemotherapy (AC) be administered to all locally advanced (clinically T3-4 or N-positivity) rectal cancer patients undergoing neoadjuvant chemoradiotherapy (nCRT) and radical surgical resection regardless of the final pathological staging (yp staging). This study aimed to evaluate the necessity of AC for ypT0-2N0 rectal cancer.

METHODS

Patients with ypT0-2N0 rectal cancer, who received nCRT and radical surgical resection, were recruited retrospectively at a university hospital. The main outcome was to evaluate the 5-year overall survival (OS) and disease-free survival (DFS) between ypT0-2N0 rectal cancer patients with AC and those without AC. We also identified potential independent prognostic factors associated with poor outcomes.

RESULTS

One hundred and ten ypT0-2N0 rectal cancer patients (ypT0: n = 6; ypT1: n = 44; ypT2: n = 60) were followed up for a median of 60 months. No significant difference was observed in DFS and 5-year OS between patients with AC and those without AC. The risk of recurrence was associated with the postoperative pathological staging (0% with ypT0, 2.4% with ypT1, and 10% with ypT2). In the multivariate analysis, retrieval of < 12 lymph nodes was an independent favorable prognostic factor, which correlated with a higher OS (HR: 2.263; 95% CI: 1.093-4.687, P = 0.028). Intra-tumor lymphovascular and perineural invasion were poor prognostic markers for shorter DFS (HR: 5.940; 95% CI: 1.150-30.696, P = 0.033).

CONCLUSION

Postoperative AC is not required for patients with ypT0-2N0 rectal cancer downstaged by nCRT, especially in those without poor prognostic factors.

Prognostic Potential of Lymphocyte-C-Reactive Protein Ratio in Patients with Rectal Cancer Receiving Preoperative Chemoradiotherapy

PURPOSE

The systemic inflammatory response is attracting increasing attention as a predictive biomarker for oncological outcome in patients with colorectal cancer. This study is aimed at verifying if the lymphocyte-C-reactive protein (CRP) ratio (LCR) could be used as a predictor of oncological outcome in patients with rectal cancer (RC) receiving preoperative chemoradiotherapy (CRT).

METHODS

We analyzed data for 86 patients with RC who received preoperative CRT followed by total mesorectal excision at our institution. A ratio of 6000 was used as the cut-off value for LCR for further analysis.

RESULTS

The post-CRT LCR was significantly lower than the pre-CRT LCR in patients with RC. Although post-CRT LCR status was not significantly correlated with overall survival (OS), low pre-CRT LCR was significantly associated with shorter recurrence-free survival (RFS: p = 0.02) and OS (p = 0.017) in this population and was an independent prognostic factor for both RFS and OS (hazard ratio (HR) 3.19, 95% confidence interval (CI) 1.33-7.66, p = 0.009; HR 2.83, 95%CI 1.14-7.01, p = 0.025, respectively). Furthermore, low pre-CRT LCR was a stronger indicator of early recurrence (p = 0.001) and poor prognosis (p = 0.025) in RC patients without pathological lymph node metastasis compared with patients with pathological lymph node metastasis, and prognostic potential of pre-CRT LCR was clearly revealed especially RC patients receiving long-course CRT.

CONCLUSIONS

Assessment of pretreatment LCR status might aid decision-making regarding postoperative treatment strategies in patients with RC receiving CRT followed by potentially curative resection.