A Meta-Analysis to Determine the Effect of Primary Tumor Resection for Stage IV Colorectal Cancer with Unresectable Metastases on Patient Survival

Background

Approximately 20 % of patients diagnosed with colorectal cancer will have distant metastases at first presentation (stage IV disease). The effect of removing the primary tumor on survival for patients with stage IV disease with unresectable metastases remains unclear. To address this a meta-analysis of all studies comparing primary tumor resection with chemotherapy alone in cases of stage IV colorectal cancer with unresectable metastases was performed.

Methods

A comprehensive search for published studies examining the effect of primary tumor resection in the setting of colorectal cancer with unresectable metastases was performed. Each study was reviewed and data extracted. Random-effects methods were used to combine data.

Results

There were 21 studies including a total of 44,226 patients that met the inclusion criteria. Resection of the primary tumor in patients with unresectable metastases compared with chemotherapy alone was associated with a lower mortality risk (OR 0.28; 95 % CI 0.165–0.474; P < 0.001), translating into a difference in mean survival of 6.4 months in favor of resection (95 % CI 5.025–7.858, P < 0.001). Patients who underwent resection of the primary tumor were more likely to have liver metastasis only (OR 1.551; 95 % CI 1.247–1.929; P < 0.001), were less likely to have ≥2 metastasis (OR 0.653; 95 % CI 0.508–0.839; P = 0.001), and were less likely to have rectal cancer (OR 0.495; 95 % CI 0.390–0.629; P < 0.001). There was significant cross-study heterogeneity.

Conclusions

Resection of the primary tumor may confer a survival advantage in stage IV colorectal cancer with unresectable metastases but significant selection bias exists in current studies. Randomized controlled trials are essential to validate these findings.     

Use of Magnetic Resonance Imaging in Detection of Breast Cancer Recurrence: A Systematic Review

Background

Diagnosis of breast cancer recurrence can be difficult as a result of the presence of scar tissue in the breast. Magnetic resonance imaging (MRI) may be superior to traditional imaging in diagnosis of recurrence because of its ability to differentiate malignancy from scarring. Current guidelines on investigation of suspected breast cancer recurrence recommend MRI when other investigations have equivocal findings. We performed the first systematic review on this topic.

Methods

Literature search revealed 35 potentially relevant studies; 10 were included in final analysis. Included were clinical studies comparing MRI with another diagnostic modality for diagnosis of breast cancer recurrence, with at least 10 patients, in the English language. Data extraction focused on sensitivity and specificity of standard diagnostic modalities and MRI for diagnosis of local disease recurrence.

Results

In total 494 patients were assessed across 10 studies; all were case series. Sensitivity of MRI for detection of recurrence ranged 75?C100?%, while specificity ranged 66.6?C100?%. Both sensitivity and specificity increased when MRI was performed after a longer time interval from the original surgery, although the longest follow-up reported was only 36?months. A negative MRI can avoid the need for further biopsy.

Conclusions

Available data are based on clinically heterogeneous case series and superiority over standard triple assessment for breast cancer recurrence has not been proven. At present, MRI cannot be recommended in the routine diagnostic assessment for breast cancer recurrence but has a potentially useful role as a second-line investigation. A negative MRI is more useful than a positive MRI as positive MRIs require further investigation.     

A Pathologic Assessment of Adequate Margin Status in Breast-Conserving Therapy

Background The definition of a clear margin in breast-conserving therapy is uncertain. The purpose of this study was to correlate the tumor-margin distance of the excision specimen with the presence of residual tumor at reoperation. We also analyzed predictors of compromised margins and of residual disease. Methods All patients who underwent breast-conserving therapy for invasive disease from 1999 to 2003 were reviewed. Pathologic characteristics and the precise tumor distance from the radial margin were recorded. A radial margin was compromised if invasive or (ductal) in situ carcinoma was <5 mm from the margin. Results Of the 612 patients who underwent breast conservation, 211 (34%) had compromised margins, and 39 had undetermined margins. Of the 161 patients who had a reoperation for compromised margins, 87 (54%) had residual disease. Residual disease after reoperation was present in 58% (56 of 96), 56% (9 of 16), and 45% (22 of 49) of those with tumor-margin distances <1 mm, ≥1 and <2 mm, and ≥2 and <5 mm, respectively. There was a progressive decline in residual disease for each millimeter until a rate of 22% for tumor-margin distances of ≥4 mm and <5 mm was reached. Pathologic size (P = .004), an extensive intraductal component (P = .002), referral from a symptomatic rather than a population-based screening program (P = .02), and the absence of a preoperative diagnosis by core biopsy (P < .0001) were predictive of compromised margins. Only young age (<45 years) was predictive of finding residual disease on reoperation (P = .02). Conclusions A total of 45% of patients who had tumor 2 to 5 mm from the radial margin had residual disease on reoperation. Our results support a policy of requiring a 5-mm margin in patients undergoing breast-conserving therapy for invasive disease.