Impact on Loco-regional Control of Radiochemotherapeutic Sequence and Time to Initiation of Adjuvant Treatment in Stage II/III Rectal Cancer Patients Treated with Postoperative Concurrent Radiochemotherapy

Patients with pathological stage N2 rectal cancer treated with early adjuvant chemotherapy have a lower treatment failure rate

Background

In this era of oxaliplatin-based adjuvant therapy, the optimal sequence in which chemoradiotherapy should be administered for pathological stage N2 rectal cancer is unknown. The aim of this study was to investigate this sequence.

Methods

In the primary adjuvant concurrent chemoradiotherapy (A-CRT) group (n = 71), postoperative concurrent chemoradiotherapy was administered before adjuvant chemotherapy. In the primary adjuvant chemotherapy (A-CT) group (n = 43), postoperative concurrent chemoradiotherapy was administered during or after adjuvant chemotherapy. Postoperative radiotherapy comprised 45–50.4 Gy in 25–28 fractions. Concurrent chemotherapy comprised two cycles of oral capecitabine (1,600 mg/m²) on days 1–14 and 22–35. Patients receiving adjuvant chemotherapy with four or more cycles of XELOX (oxaliplatin plus capecitabine) or eight or more cycles of FOLFOX (fluorouracil, leucovorin, and oxaliplatin) were included.

Results

Between June 2005 and December 2013, data for 114 qualified rectal cancer patients were analyzed. The percentages of patients in whom treatment failed in the A-CRT and A-CT groups were 33.8% and 16.3%, respectively (p = 0.042). More patients had distant metastases in the A-CRT group than in the A-CT group (32.4% vs. 14.3%, p = 0.028). Multivariate analysis indicated that the sequence in which chemoradiotherapy was administered (A-CT vs. A-CRT) was an independent prognostic factor for both estimated disease-free survival [hazard ratio (HR) 0.345, 95% confidence interval (CI) 0.137–0.868, p = 0.024] and estimated distant metastasis-free survival (HR 0.366, 95% CI 0.143–0.938, p = 0.036).

Conclusions

In pathological stage N2 rectal cancer patients, administering adjuvant chemotherapy before chemoradiotherapy led to a lower rate of treatment failure, especially with respect to distant metastasis. Adjuvant chemotherapy prescribed as early as possible might benefit this cohort of patients in this era of oxaliplatin-based adjuvant therapy.

Less than 12 lymph nodes in the surgical specimen after neoadjuvant chemo-radiotherapy: an indicator of tumor regression in locally advanced rectal cancer?

BACKGROUND

The number of lymph node retrieved in the surgical specimen is important for tumor staging and has paramount impact on prognosis in colorectal cancer and imitates the adequacy of lymph node surgical clearance. The paucity of lymph node yields in patients undergoing resection after preoperative chemo radiotherapy (CRT) in rectal cancer has seen. Lower total number of lymph nodes in the total mesoractal excision (TME) specimen after CRT, could a marker of better tumor response.

METHODS

We retrospectively reviewed the prospectively managed data of patients underwent excision for rectal cancer, who treated by neoadjuvant radiotherapy with or without chemotherapy in locally advanced rectal cancer. From 2010 to 2014, 364 patients underwent rectal cancer surgery, of which ninety-one treated with neoadjuvant treatment. Standard surgical and pathological protocols were followed. Patients were categorized into two groups based on the number of total harvested lymph nodes with group 1, having 12 or more nodes harvested, and group 2 including patients who had <12 lymph nodes harvested. The total number of lymph nodes retrieved from the surgical specimen was correlated with grade of tumor regression with neoadjuvant treatment.

RESULTS

Out of 91 patients, 38 patients (42%) had less than 12 lymph nodes examined in specimen. The difference in median number of lymph nodes was observed significantly as 9 (range, 2-11) versus 16 (range, 12-32), in group 2 and 1, respectively (P<0.01). Patients with fewer lymph node group were comparable with respect to age, BMI, pre-operative staging, neoadjuvant treatment. Pathological complete response in tumor pCR was seen with significantly higher rate (40% vs. 26%, P<0.05) in group 2. As per Mandard criteria, there was significant difference in tumor regression grade (TRG) between both the groups (P<0.05). Among patients with metastatic lymph nodes, median LNR was lower in <12 lymph nodes group at 0.167 (range, 0.09-0.45) versus 0.187 (range, 0.05-0.54), difference was not statistically significant (P=0.81).

CONCLUSIONS

Retrieval of fewer than 12 lymph nodes in surgical specimen of rectal cancer who had received neo-adjuvant radiotherapy with or without chemotherapy should be considered as a good indicator of tumor response with better local disease control, and a good prognostic factor, rather than as a pointer of poor diligence of the surgical and pathological assessment.

Significance of histologic tumor grade in rectal cancer treated with preoperative chemoradiotherapy followed by curative surgery: A multi-institutional retrospective study

BACKGROUND AND PURPOSE

To evaluate the pre-treatment clinical factors affecting recurrence and survival in rectal cancer patients who receive preoperative chemoradiotherapy (CRT) and curative surgery.

METHODS AND MATERIALS

The clinical data of 1782 patients from 8 institutions in Korea were analyzed. The potential prognostic factors that could be acquired before radical surgery were patient age, gender, clinical T and N stages, tumor size and location, tumor grade, carcinoembryonic antigen (CEA) level, and the concurrent chemotherapy regimen. The relapse-free survival (RFS), overall survival (OS), and cumulative incidence of locoregional and distant recurrence were analyzed according to the clinical factors.

RESULTS

Among the pre-treatment clinical factors, tumor grade, pre-CRT CEA level, tumor location, and clinical N stage were significant prognostic factors affecting the RFS. The high-grade tumor was the hazardous factor for RFS on the multivariate analysis [Hazard ratio (HR), 1.83; 95% confidence interval (CI), 1.29-2.58; p=0.001]. The 5-year RFS rate for high-grade tumors was significantly lower than that for low-grade tumors (63.8% vs. 78.8%, p<0.001). The tumor grade was a significant prognostic factor for distant recurrence (HR, 1.83, 95% CI, 1.29-2.58; p<0.001), but not for locoregional recurrence (HR, 1.49, 95% CI, 0.68-3.26; p=0.320) on the multivariate analysis. The 5-year OS rate for high-grade tumors was significantly lower than that for low-grade tumors (70.6% vs. 85.5%, p<0.001).

CONCLUSION

The tumor grade is the significant pre-treatment clinical factor for recurrence and survival in rectal cancer patients who receive preoperative CRT and curative surgery.

Impact of Lymph Node Ratio on Oncologic Outcomes in ypStage III Rectal Cancer Patients Treated with Neoadjuvant Chemoradiotherapy followed by Total Mesorectal Excision, and Postoperative Adjuvant Chemotherapy

PURPOSE

To evaluate the prognostic impact of the lymph node ratio (LNR) in ypStage III rectal cancer patients who were treated with neoadjuvant chemoradiotherapy (NCRT).

MATERIALS AND METHODS

We retrospectively reviewed the data of 638 consecutive patients who underwent NCRT followed by total mesorectal excision, and postoperative adjuvant chemotherapy for rectal cancer from 2004 to 2011. Of these, 125 patients were positive for lymph node (LN) metastasis and were analyzed in this study.

RESULTS

The median numbers of examined and metastatic LNs were 17 and 2, respectively, and the median LNR was 0.143 (range, 0.02-1). Median follow-up time was 55 months. In multivariate analyses, LNR was an independent prognostic factor for overall survival (OS) (hazard ratio [HR] 2.17, p = 0.041), disease-free survival (DFS) (HR 2.28, p = 0.005), and distant metastasis-free survival (DMFS) (HR 2.30, p = 0.010). When ypN1 patients were divided into low (low LNR ypN1 group) and high LNR (high LNR ypN1 group) according to a cut-off value of 0.152, the high LNR ypN1 group had poorer OS (p = 0.043) and DFS (p = 0.056) compared with the low LNR ypN1 group. And there were no differences between the high LNR ypN1 group and the ypN2 group in terms of the OS (p = 0.703) and DFS (p = 0.831).

CONCLUSIONS

For ypN-positive rectal cancer patients, the LNR was a more effective prognostic marker than the ypN stage, circumferential resection margin, or tumor regression grade after NCRT, and could be used to discern the high-risk group among ypN1 patients.