Efficacy and tolerability of preoperative chemoradiotherapy with S-1 alone for locally advanced rectal cancer

Relationship between histopathological therapeutic effect and prognosis in oral cancer patients after preoperative S-1 chemotherapy followed by surgery

OBJECTIVES

Preoperative S-1 chemotherapy is administered to prevent tumor proliferation before surgery in oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the relationship between the histological therapeutic effect and prognosis in patients with OSCC after pre-operative S-1 chemotherapy.

MATERIALS AND METHODS

Among 461 OSCC cases, 281 patients who received preoperative S-1 chemotherapy were compared with 180 patients that did not receive chemotherapy to determine the histological therapeutic effect in the resected specimens and the differences in relapse-free survival.

RESULTS

The histological chemotherapeutic effect was well correlated with the subsequent prognosis. In an examination of the combined effect of treatment and ypStage, the groups with good S-1 treatment effects had extremely good prognoses, even if the postoperative resection specimens were within the same ypStage. In a stratified search of patients who received S-1 for more than 7 days and who had a significantly better prognosis than those who did not receive S-1, it was found that the prognosis was significantly better for patients with tongue cancer according to site; furthermore, tongue cancer, age under 70 years of age, male sex, and clinical stage I were factors associated with a significantly better prognosis.

CONCLUSIONS

Even if the postoperative resection specimens were within the same ypStage, the groups that responded to S-1 treatment were considered to have extremely good prognoses.

CLINICAL RELEVANCE

A good adaptation for S-1 was tongue cancer, and especially tongue cancer with cStage I, male sex, and age less than 70 years old.

Efficacy and safety of preoperative chemoradiotherapy with S-1 for advanced rectal cancer: a phase II study

Background

Preoperative chemoradiotherapy (CRT) for patients with rectal cancer is not yet established in Japan. We aimed to evaluate the efficacy and safety of preoperative CRT with S-1, a fixed-dose combination of tegafur, gimeracil, and oteracil potassium.

Materials and methods

We conducted a prospective, interventional, non-randomized single-center study. Radiotherapy was administered at a total dose of 45 Gy (1.8 Gy in 25 fractions) for five weeks. S-1 was administered orally for nine weeks (five weeks during and four weeks after radiotherapy) at a dose of 80 mg/m²/day. The endpoint was the pathological complete response (pCR) rate.

Results

Twenty-eight patients were finally enrolled. The following patient characteristics were recorded: clinical Stage (II: n = 12, III: n = 16), median age (66 years, range 40-77 years), male/female ratio (20/8), and lesion site (Ra-Rb:3/Rb:23/Rb-P:2). Preoperative treatment was completed in 27 patients (96%). Treatment abandonment occurred because of diarrhea. Grade 3 or higher adverse events were observed in one (4%) patient with two events. No serious adverse events occurred in the ≥ 70 years group. The response rate was 68% in all patients and 68% among elderly patients. Radical resection was achieved in all patients, including 19 (68%) who underwent sphincter-preserving surgery. The pCR rate was 11% (three patients). The five-year disease-free survival rate was 68%, and the overall survival rate was 82%. Local recurrence occurred in only one patient five years after surgery.

Conclusion

Preoperative CRT with S-1 alone may be a safe and acceptable regimen from the perspective of adverse events and oncological outcomes.

Trial registration

UMIN Clinical Trial Registry: UMIN000013598. Registered 1 April 2014, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recpt-no=R000015887.