Prognostic factors in patients with high-risk stage II colon cancer after curative resection: a post hoc analysis of the JFMC46-1201 trial

PURPOSE

The goal of the current study was to identify prognostic factors for disease-free survival (DFS) and overall survival (OS) in high-risk stage II colon cancer.

METHODS

The subjects were patients with histologically confirmed stage II colon cancer undergoing R0 resection who met at least one of the following criteria: T4, perforation/penetration, poorly differentiated adenocarcinoma, mucinous carcinoma, and < 12 examined lymph nodes. Patients self-selected surgery alone or a 6-month oral uracil and tegafur plus leucovorin (UFT/LV) regimen. Serum CEA mRNA at ≥ 24 h after surgery and < 2 weeks after registration was also examined as a potential prognostic factor for stage II colon cancer. This study is registered with UMIN-CTR (protocol ID: UMIN000007783).

RESULTS

1880 were included in the analysis to identify prognostic factors for DFS and OS in patients with high-risk stage II colon cancer. In multivariate analyses, gender, depth of tumor invasion, extent of lymph node dissection, number of examined lymph nodes, and postoperative adjuvant chemotherapy (POAC) emerged as significant independent prognostic factors for DFS. Similarly, multivariate analysis showed that age, gender, depth of tumor invasion, perforation/penetration, extent of lymph node dissection, number of examined lymph nodes, and POAC were significant independent prognostic factors for OS. Univariate analyses showed no significant difference in DFS or OS for CEA mRNA-positive and mRNA-negative cases.

CONCLUSION

This study showed that gender, depth of tumor invasion, extent of lymph node dissection, number of examined lymph nodes, and lack of use of POAC were significant independent prognostic factors in stage II colon cancer.

Randomized phase II study of tegafur-uracil/leucovorin versus tegafur-uracil/leucovorin plus oxaliplatin after curative resection of high-risk stage II/III colorectal cancer (SOAC-1101 trial)

PURPOSE

This randomized phase II trial compared tegafur-uracil/leucovorin (UFT/LV) plus oxaliplatin (TEGAFOX) to UFT/LV as adjuvant chemotherapy for patients with high-risk stage II/III colorectal cancer.

METHODS

From 2010 to April 2015, 159 patients who underwent curative resection were randomly assigned to receive TEGAFOX (85 mg/m² oxaliplatin on days 1 and 15, 300 mg/m²/day UFT and 75 mg/day LV on days 1-28, every 35 days for five cycles) or UFT/LV. The primary study endpoint was disease-free survival.

RESULTS

The 3-year disease-free survival rate was 84.2% in the TEGAFOX arm, versus 62.1% for UFT/LV. The stratified hazard ratio for disease-free survival for TEGAFOX compared to UFT/LV was 0.338 (P < 0.01). The incidence of any-grade adverse events was significantly higher in the TEGAFOX arm (96.1%) than in the UFT/LV arm (76.6%; P < 0.01). The rates of any-grade neutropenia, thrombocytopenia, aspartate aminotransferase/alanine aminotransferase elevation, and peripheral sensory neuropathy were higher in the TEGAFOX group, whereas the incidence of grade ≥ 3 adverse events did not differ between the groups.

CONCLUSIONS

TEGAFOX is an additional adjuvant chemotherapy option for high-risk stage II/III colorectal cancer.

TRIAL REGISTRATION

UMIN ID: 000007696, date of registration: April 10, 2012.

Treatment Rationale and Study Design for Clinical Trial on the Efficacy of UFT/LV for Stage II Colorectal Cancer With Risk Factors for Recurrence (JFMC46-1201)

BACKGROUND

The usefulness of adjuvant chemotherapy for stage II colon cancer has not been established. Meanwhile, the presence of stage II colon cancer with high-risk factors for recurrence has been reported. To our knowledge, no prospective study of adjuvant chemotherapy for stage II colon cancer with high-risk factors has been implemented to date.

PATIENTS AND METHODS

This study is a prospective nonrandomized controlled study based on patients' selection of treatment option, including randomized therapeutic decision-making, to evaluate the usefulness of adjuvant chemotherapy with tegafur-uracil (UFT) with leucovorin (LV) for stage II colon cancer with high-risk factors for recurrence, compared with surgery alone. Five courses of UFT/LV therapy will be given as follows: UFT (300 mg/m(2)/d) with LV (75 mg/d) will be orally administered in 3 doses per day. Treatment will be received daily for 28 days, followed by a 7-day rest or will be received daily for 5 days, followed by a 2-day rest. For both regimens, 1 course will last 5 weeks, and 5 courses will be given. The primary end point is disease-free survival. A propensity score matching will be conducted based on 7 variables that represent risk factors to minimize selection bias in a comparison between the nonrandomized arms. For this nonrandomized comparison, a target sample size is set at 1200 (400 and 800 patients for the surgery alone and UFT/LV groups, respectively) and 1720 patients will be enrolled. In this study we aim to evaluate the therapeutic usefulness of adjuvant chemotherapy with UFT/LV for stage II colorectal cancer with risk factors for recurrence.