18Fluoro-deoxy-glucose positron emission tomography in assessing tumor response to preoperative chemoradiation therapy for locally advanced rectal cancer.

BACKGROUND: This study aims to evaluate the efficacy of (18)F-FDG PET in assessing tumor response after preoperative chemoradiation therapy (CRT) for rectal cancer. METHODS: Maximum standardized uptake value (SUV) was measured for 37 patients who underwent (18)F-FDG PET before and 4 weeks after completion of preoperative CRT. Pre-SUV, post-SUV, the difference between pre- and post-SUV (ΔSUV), and reduction rate (RR) were correlated with tumor response. RESULTS: A lower mean post-SUV and a higher mean RR were shown in good tumor response (T-downstaging(+) and tumor regression grade 1, 2). Considering pathologic complete response (pCR), the mean post-SUV and the mean RR were significantly different between pCR (+) patients (N = 13) and pCR (-) patients (N = 24) (2.7 vs. 4.8, P < 0.001, 73.9% vs. 58.7%, P = 0.009). With a 3.35 cut-off value for the post-SUV by receiver operating characteristic analysis, 84.6% sensitivity, 79.2% specificity, and 81.2% overall accuracy were obtained for discriminating between pCR (+) and pCR (-) (area under the curve = 0.885, P < 0.001). CONCLUSIONS: (18)F-FDG PET is potentially useful as a method for assessing tumor response after preoperative CRT for rectal cancer. Post-SUV and RR were significantly associated with pathological treatment response, especially in pCR.

The prognostic impact of the number of lymph nodes retrieved after neoadjuvant chemoradiotherapy with mesorectal excision for rectal cancer.

BACKGROUND: We aimed to assess factors associated with the number of nodes retrieved and the impact of the number of lymph nodes in rectal cancer patients who underwent neoadjuvant chemoradiation with radical surgery. METHODS: A total of 258 patients were enrolled. Lymph nodes were retrieved from specimens using a manual dissection technique. RESULTS: Of the 258 patients, nine patients had an absence of lymph nodes (ypNx), 150 patients had a node-negative status (ypN(-)) and 99 patients had node-positive disease (ypN(+)). An advanced ypT classification (ypT3,4) and larger tumor (>4 cm) were associated with an increased number of nodes retrieved. The pretreatment CEA level (>5 ng/ml) and ypN(+) classification were significant risk factors for cancer specific and recurrence free survival. There was no significant difference of oncological outcomes among ypNx patients and a subset of ypN(-) patients based on the number of nodes retrieved using three cutoff values (1-11, 12-25, and 25-65 nodes). CONCLUSIONS: In a neoadjuvant setting, ypN(+) disease was an independent risk factor for oncological outcomes. An absence of nodes does not represent an inferior oncological outcome. The number of nodes does not seen to impact survival and recurrence in ypN(-) patients.

Prognostic factors affecting oncologic outcomes in patients with locally recurrent rectal cancer: impact of patterns of pelvic recurrence on curative resection.

BACKGROUND: The purpose of this study is to investigate prognostic factors affecting oncologic outcomes in patients with locally recurrent rectal cancer and determine whether recurrence patterns influence curative resection of recurrent tumor. MATERIALS AND METHODS: We examined 62 patients with isolated local recurrence following total mesorectal excision (TME) of the primary rectal cancer. Recurrence patterns were classified as central, anterior, posterior, lateral, and perineal with respect to the intra-pelvic tumor location. Prognostic factors affecting oncologic outcomes were analyzed, and the rate of curative resection was analyzed according to recurrence patterns. RESULTS: The mean follow-up period was 49.0 +/- 29.0 months, and the mean time to recurrence after TME was 27.9 +/- 23.3 months. Twenty-three patients underwent curative resection, and the remaining 39 patients received palliative treatment. Patients with a central recurrence had the highest rate of curative resection (p = 0.006). The overall 5-year survival rate was 13.9% and significantly higher in those treated with curative resection (35.1%; p = 0.0002). Multivariate analysis demonstrated that disease-free survival less than 1 year and curative resection of local recurrence were independent prognostic factors influencing 5-year survival. CONCLUSION: Patients with central recurrences have a high probability of curative resection. Disease-free survival less than 1 year and curative resection of local recurrence were independent prognostic factors affecting oncologic outcomes in patients with locally recurrent rectal cancer.

Cetuximab in combination with 5-fluorouracil, leucovorin and irinotecan as a neoadjuvant chemotherapy in patients with initially unresectable colorectal liver metastases.

BACKGROUND: The efficacy and safety of a combination of cetuximab, irinotecan, and 5-fluorouracil/leucovorin (FOLFIRI) in downsizing unresectable colorectal liver metastases was investigated. PATIENTS AND METHODS: Patients with unresectable colorectal liver metastases with or without resectable extrahepatic metastasis were enrolled. 23 patients initially received 400 mg/m2 of cetuximab, followed by a weekly infusion of 250 mg/m2 and a biweekly dose of irinotecan (180 mg/m2), with 5-fluorouracil both by bolus (400 mg/m2) and by a 46-h infusion (total of 2,400 mg/m2) with leucovorin (400 mg/m2). RESULTS: The overall response rate was 39.1% (n = 9; 95% confidence interval (CI): 17.6-60.7%). The most common grade 3-4 toxicities were skin reactions (30.4%) and diarrhea (26.1%). The rate of conversion to resectable liver metastases was 30.4% (n = 7; 95% CI: 10.1-50.8%). The factors found to be significantly associated with R0 resection were lower serum carcinoembryonic antigen levels after chemotherapy (p = 0.039), being chemonaive (p = 0.002), and showing a higher incidence of grade 3-4 skin toxicity (p = 0.011). CONCLUSIONS: Cetuximab with FOLFIRI may be an effective and safe treatment option for downsizing unresectable colorectal liver metastases.