Phase I/II trial of preoperative chemoradiotherapy with capecitabine and oxaliplatin in locally advanced rectal cancer

Chromosomal copy number changes of locally advanced rectal cancers treated with preoperative chemoradiotherapy

Standard treatment of rectal cancer patients comprises preoperative chemoradiotherapy followed by radical surgery. However, clinicians are faced with the problem that response rates vary from one individual to another. Predictive biomarkers would therefore be helpful. To identify genomic imbalances that might assist in stratifying tumors into responsive or nonresponsive categories, we used metaphase comparative genomic hybridization to prospectively analyze pretherapeutic biopsies from 42 patients with locally advanced rectal cancers. These patients were subsequently treated with 5-fluorouracil-based preoperative chemoradiotherapy. Based on downsizing of the T-category, 21 rectal cancers were later classified as responsive, while the other 21 were nonresponsive. Comparing these two groups, we could show that gains of chromosomal regions 7q32 approximately q36 and 7q11 approximately q31, as well as amplifications of 20q11 approximately q13, were significantly associated with responsiveness to preoperative chemoradiotherapy (P<0.05). However, the probability of detecting these copy number changes by chance is high (P=0.21). Our primary results suggest that pretherapeutic evaluation of chromosomal copy number changes may be of value for response prediction of rectal cancers to preoperative chemoradiotherapy. This will require validation in a larger cohort of patients.

Neoplastic mesorectal microfoci (MMF) following neoadjuvant chemoradiotherapy: clinical and prognostic implications

BACKGROUND

Neoplastic microfoci have frequently been found in the mesorectum, with poor outcome. In this study, incidence and clinical significance of mesorectal microfoci (MMF) were analyzed in patients operated on for rectal cancer following neoadjuvant chemoradiation.

METHODS

A case series of 68 patients with extraperitoneal rectal cancer treated with neoadjuvant chemoradiation and surgery (including total mesorectal excision) were investigated for presence of neoplastic MMF.

RESULTS

MMF were found in 26 cases (38.2%). Increasing incidence of microfoci was statistically related to pathologic involvement of the bowel wall (P = 0.0006), Mandard's tumor regression grading (P = 0.0006), and pathologic neoplastic mesorectal involvement (P < 0.00001). None of the nine patients with complete tumor disappearance displayed both microfoci and lymph node metastasis. Only one local recurrence developed in a patient with multiple MMF. One out of nine pT0 or TRG1 patients (11.1%) had distant metastases compared with 15 out of 59 pT1-4 or TRG2-5 (25.4%, P = 0.70).

CONCLUSIONS

A remarkable incidence of MMF was found following chemoradiation. However, when this therapy induced complete regression of primary tumor (pT0-TRG1), we found that node metastases and neoplastic MMF also disappeared. These features should be confirmed to assess the impact of these microfoci in treatment decision making in rectal cancers.

Neoplastic mesorectal microfoci (MMF) following neoadjuvant chemoradiotherapy: clinical and prognostic implications

BACKGROUND

Neoplastic microfoci have frequently been found in the mesorectum, with poor outcome. In this study, incidence and clinical significance of mesorectal microfoci (MMF) were analyzed in patients operated upon for rectal cancer following neoadjuvant chemoradiation.

METHODS

A case series of 68 patients with extraperitoneal rectal cancer, treated with neoadjuvant chemoradiation and surgery (including total mesorectal excision), was investigated for the presence of neoplastic MMF.

RESULTS

Mesorectal microfoci were found in 26 cases (38.2%). Increasing incidence of microfoci was statistically related to pathologic involvement of bowel wall (P = 0.0006), Mandard's tumor regression grading (P = 0.0006) and pathologic neoplastic mesorectal involvement (P < 0.00001). None of the nine patients with complete tumor disappearance displayed both microfoci and lymph node metastasis. Only one local recurrence developed in a patient with multiple MMF. Out of 9 pT0 or TRG1 patients, 1 (11.1%) had distant metastases, compared to 15 out of 59 pT1-4 or TRG2-5 (25.4%, P = 0.70).

CONCLUSIONS

A remarkable incidence of MMF was found following chemoradiation. However, when this therapy induces complete regression of primary tumor (pT0-TRG1), node metastases and neoplastic MMF could also disappear, as shown in our cases. These features should be confirmed because they could significantly impact the treatment decision-making of rectal cancers.

Capecitabine Versus Continuous-Infusion 5-Fluorouracil for Colorectal Cancer: A Retrospective Efficacy and Safety Comparison

For more than 40 years, 5-fluorouracil (5-FU) has been considered the most effective systemic agent for managing advanced colorectal cancer. However, continuous-infusion (CI) schedules of 5-FU require central venous access devices, which are associated with catheter complications and are an inconvenience to patients. The novel oral fluoropyrimidine capecitabine appears to offer comparable efficacy while providing a more convenient schedule that is often preferred by patients. Published phase II/III clinical studies of capecitabine-based regimens for colorectal cancer were compared with key studies of CI 5-FU-based regimens to assess safety, efficacy, quality of life, and pharmacoeconomics. Studies were identified via Medline searches and conference abstracts dating back to 1997. Qualitative analyses show that capecitabine as a single agent as well as in combination regimens is an effective first-line treatment for metastatic colorectal cancer, providing a higher response rate compared with standard 5-FU/leucovorin. Costs associated with capecitabine also appear to be lower than those associated with catheter-based therapies. Capecitabine offers physicians a more convenient treatment for advanced colorectal cancer, with manageable toxicity and antitumor activity comparable to that of CI therapies.