Adjuvant treatment may benefit patients with high-risk upper rectal cancer: A nomogram and recursive partitioning analysis of 547 patients

Postoperative chemoradiotherapy with capecitabine and oxaliplatin vs. capecitabine for pathological stage N2 rectal cancer

Objective

Several studies have been conducted on the effects and toxicity of adding oxaliplatin to fluorouracil-based or capecitabine-based chemoradiotherapy (CRT) regimens as significantly increasing the toxic response without benefit to survival. In this study, we further explored the role of these two postoperative CRT regimens in patients with pathological stage N2 rectal cancer.

Methods

This study was a subgroup analysis of a randomized clinical trial. A total of 180 patients with pathological stage N2 rectal cancer were eligible, 85 received capecitabine with radiotherapy (RT), and 95 received capecitabine and oxaliplatin with RT. Patients in both groups received adjuvant chemotherapy [capecitabine and oxaliplatin (XELOX); or fluorouracil, leucovorin, and oxaliplatin (FOLFOX)] after CRT.

Results

At a median follow-up of 59.2 [interquartile range (IQR), 34.0-96.8] months, the three-year disease- free survival (DFS) was 53.3% and 64.9% in the control group and the experimental group, respectively [hazard ratio (HR), 0.63; 95% confidence interval (95% CI), 0.41-0.98; P=0.04]. There was no significant difference between the groups in overall survival (OS) (HR, 0.62; 95% CI, 0.37-1.05; P=0.07), the incidence of locoregional recurrence (HR, 0.62; 95% CI, 0.24-1.64; P=0.33), the incidence of distant metastasis (HR, 0.67; 95% CI, 0.42-1.06; P=0.09) and grade 3-4 acute toxicities (P=0.78). For patients with survival longer than 3 years, the conditional overall survival (COS) was significantly better in the experimental group (HR, 0.39; 95% CI, 0.16-0.96; P=0.03).

Conclusions

Our results indicated that adding oxaliplatin to capecitabine-based postoperative CRT is safe and effective in patients with pathological stage N2 rectal cancer.

The number of cycles of adjuvant chemotherapy in stage III and high-risk stage II rectal cancer: a nomogram and recursive partitioning analysis

Objective

The prognostic role of the number of cycles of adjuvant chemotherapy (ACT) after total mesorectal excision in stage III and high-risk stage II rectal cancer is unknown. As a result of this, our study was designed to assess the effect of the number of cycles of ACT on the prediction of cancer-specific survival.

Methods

Four hundred patients that were diagnosed as stage III and high-risk stage II rectal cancer from January 2012 to January 2018 and who had received total mesorectal excision were enrolled in this study. A nomogram incorporating the number of cycles of ACT was also developed in this study. For internal validation, the bootstrap method was used and the consistency index was used to evaluate the accuracy of the model. The patients were stratified into risk groups according to their tumor characteristics by recursive partitioning analysis.

Results

We found that the risk of death was decreased by 26% (HR = 0.74, 95% CI: 0.61–0.89, P = 0.0016) with each increasing ACT cycle. The N stage, positive lymph node ratio (PLNR), carcinoembryonic antigen, neutrophil-to-lymphocyte ratio, and the number of cycles of ACT were chosen and entered into the nomogram model. Recursive partitioning analysis-based risk stratification revealed a significant difference in the prognosis in rectal cancer patients with high-risk, intermediate-risk, and low-risk (3-year cancer-specific survival: 0.246 vs. 0.795 vs. 0.968, P < 0.0001). Seven or more cycles of ACT yielded better survival in patients with PLNR ≥ 0.28 but not in patients with PLNR < 0.28.

Conclusion

In conclusion, the nomogram prognosis model based on the number of cycles of ACT predicted individual prognosis in rectal cancer patients who had undergone total mesorectal excision. These findings further showed that in patients with PLNR ≥ 0.28, no fewer than 7 cycles of ACT are needed to significantly reduce the patient’s risk of death.

Which Definition of Upper Rectal Cancer Is Optimal in Selecting Stage II or III Rectal Cancer Patients to Avoid Postoperative Adjuvant Radiation?

BACKGROUND

In most guidelines, upper rectal cancers (URC) are not recommended to take neoadjuvant or adjuvant radiation. However, the definitions of URC vary greatly. Five definitions had been commonly used to define URC: 1) >10 cm from the anal verge by MRI; 2) >12 cm from the anal verge by MRI; 3) >10 cm from the anal verge by colonoscopy; 4) >12 cm from the anal verge by colonoscopy; 5) above the anterior peritoneal reflection (APR). We hypothesized that the fifth definition is optimal to identify patients with rectal cancer to avoid adjuvant radiation.

METHODS

The data of stage II/III rectal cancer patients who underwent radical surgery without preoperative chemoradiotherapy were retrospectively reviewed. The height of the APR was measured, and compared with the tumor height measured by digital rectal examination (DRE), MRI and colonoscopy. The five definitions were compared in terms of prediction of local recurrence, survival, and percentages of patients requiring radiation.

RESULTS

A total of 576 patients were included, with the intraoperative location of 222 and 354 tumors being above and straddle/below the APR, respectively. The median distance of the APR from anal verge (height of APR) as measured by MRI was 8.7 (range: 4.5-14.3) cm. The height of APR positively correlated with body height (r=0.862, P<0.001). The accuracy of the MRI in determining the tumor location with respect to the APR was 92.1%. Rectal cancer above the APR had a significantly lower incidence of local recurrence than those straddle/below the APR (P=0.042). For those above the APR, there was no significant difference in local recurrence between the radiation and no-radiation group. Multivariate analyses showed that tumor location regarding APR was an independent risk factor for LRFS. Tumor height as measured by DRE, MRI and colonoscopy were not related with survival outcomes. Fewer rectal cancer patients required adjuvant radiation using the definition by the APR, compared with other four definitions based on a numerical tumor height measured by MRI and colonoscopy.

CONCLUSIONS

The definition of URC as rectal tumor above the APR, might be the optimal definition to select patients with stage II/III rectal cancer to avoid postoperative adjuvant radiation.

Analysis of specific survival and local control through a recursive partitioning analysis in patients with head and neck carcinoma

INTRODUCTION AND OBJECTIVES

Recursive partitioning analysis (RPA) is a technique that allows prognostic classification in oncological patients. The aim of the present study is to analyse by means of an RPA a cohort of patients with squamous carcinomas of the head and neck (SCHN).

METHODS

5,226 SCHN were retrospectively analysed with an RPA, considering the specific survival and local control of the disease as dependent variables. A cohort of patients was used for the creation of the classification model, and another cohort was used to carry out its internal validation.

RESULTS

Considering specific survival as a dependent variable we obtained a classification tree with 14 terminal nodes that were grouped into 5 categories, including as partition variables the local and regional extent of the tumour, and the location of the tumour. When considering the local control of the disease as a dependent variable we obtained a classification tree with 10 terminal nodes that were grouped into 4 categories, including as partition variables the local extension and location of the tumour, the type of treatment performed, the age of the patient, and if it was a first tumour or a subsequent neoplasm. The validation study confirmed the prognostic capacity of the models developed with the RPA. One of the advantages of the RPA is that it allows the identification of groups of patients with specific behaviour.

CONCLUSION

RPA is shown to be an effective technique for the prognostic classification of patients with a SCHN.