MRI and FDG-PET for assessment of response to neoadjuvant chemotherapy in locally advanced rectal cancer.

BACKGROUND: The purpose of this study was to assess the value of magnetic resonance imaging (MRI) and additional (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for tumor response to neoadjuvant chemotherapy (NAC) in patients with locally advanced rectal cancer (LARC). METHODS: Data on 40 patients with LARC, who were treated with NAC and underwent MRI and FDG-PET/CT before and after NAC, were analyzed retrospectively. Surgery was performed at a median of 6 weeks after NAC and the images were compared with the histological findings. The tumor regression grade 3/4 was classified as a responder. RESULTS: Sixteen patients were pathological responders. Receiver operating characteristic (ROC) analysis revealed that MRI total volume after NAC (MRI-TV2) and ΔMRI-TV had the highest performance to assess responders (area under the ROC curve [AUC] 0.849 and AUC 0.853, respectively). The reduction rate of the maximum standardized uptake value (ΔSUVmax) was also an informative factor (AUC 0.719). There seems no added value of adding FDG-PET/CT to MRI-TV2 and ΔMRI-TV in assessment of NAC responders judging from changes in AUC (AUC of ΔSUVmax and MRI-TV2 was 0.844, and AUC of ΔSUVmax and ΔMRI-TV was 0.846). CONCLUSIONS: MRI-TV2 and ΔMRI-TV were the most accurate factors to assess pathological response to NAC. Although ΔSUVmax by itself was also informative, the addition of FDG-PET/CT to MRI did not improve performance. Patients with LARC who were treated by induction chemotherapy should receive an MRI examination before and after NAC to assess treatment response. A more than 70 % volume reduction shown by MRI volumetry may justify the omission of subsequent radiotherapy.

Neoadjuvant oxaliplatin and capecitabine and bevacizumab without radiotherapy for poor-risk rectal cancer: N-SOG 03 Phase II trial.

OBJECTIVE: This Phase II trial was designed to evaluate the safety and efficacy of neoadjuvant oxaliplatin and capecitabine and bevacizumab without radiotherapy in patients with poor-risk rectal cancer. METHODS: Patients with magnetic resonance imaging-defined poor-risk rectal cancer received neoadjuvant oxaliplatin and capecitabine and bevacizumab followed by total mesorectal excision or more extensive surgery. RESULTS: Between February 2010 and December 2011, 32 patients were enrolled in this study. The completion rate of the scheduled chemotherapy was 91%. Reasons for withdrawal were refusal to continue therapy in two patients and disease progression in one, with two of these three patients not undergoing surgery. Among the 29 patients who completed the scheduled chemotherapy, one refused surgery within 8 weeks after the completion of chemotherapy, which was the period stipulated by the protocol, and another had rectal perforation, requiring urgent laparotomy. As a result, the completion rate of this experimental treatment was 84%. Of the 30 patients who underwent surgery, the R0 resection rate was 90% and a postoperative complication occurred in 43%. A pathological complete response was observed in 13% and good tumor regression was exhibited in 37%. CONCLUSIONS: Neoadjuvant oxaliplatin and capecitabine plus bevacizumab for poor-risk rectal cancer caused a high rate of anastomotic leakage and experienced a case with perforation during chemotherapy, both of which were bevacizumab-related toxicity. Although the short-term results with the completion rate of 84.4% and the pathological complete response rate of 13.3% were satisfactory, we have to reconsider the necessity of bevacizumab in neoadjuvant chemotherapy (UMIN number, 000003507).

[A case of mediastinal lymph node gastric cancer recurrence during S-1 adjuvant therapy successfully treated with cisplatin + capecitabine as second-line chemotherapy].

S-1 adjuvant chemotherapy following radical surgery has been the standard therapy for the pStage II/III gastric cancer in Japan. However, there are few reports regarding treatment for gastric cancer recurrence during S-1 therapy. Here, we present a case of recurrent gastric cancer during S-1 adjuvant therapy that showed partial response to CDDP + capecitabine therapy. A 72-year-old man was diagnosed as having gastric cancer. We performed a distal gastrectomy+D2 dissection, with Roux-en Y reconstruction. The patient was treated with S-1 for adjuvant chemotherapy. Six months after operation, multiple mediastinal lymph node recurrence developed. CDDP + CPT-11 was applied for two courses as first-line treatment for the recurrence. However, the disease progressed with worsening mediastinal lymph node metastases (progressive disease). After two courses of CDDP + capecitabine as second-line chemotherapy, the recurrence site became smaller. After five courses, partial response (PR) had been achieved. Two years and five months after gastrectomy, capecitabine monotherapy was applied as third-line chemotherapy.