Comparison of breast-conserving therapy with mastectomy for treatment of early breast cancer in community hospitals

A Network Meta-Analysis of Surgical Treatment in Patients With Early Breast Cancer

BACKGROUND

In early breast cancer treatment, the preferred surgical regimen remains a topic of controversy, and conventional pairwise meta-analysis cannot provide a hierarchy based on clinical trial evidence. Therefore, a network meta-analysis was performed both for direct and indirect comparisons and to assess the survival outcomes of surgical regimens.

METHODS

Randomized clinical trials comparing different surgical regimens for the treatment of early breast cancer were identified. Overall survival (OS) and disease-free-survival (DFS) were analyzed using random-effects network meta-analysis on the hazard ratio (HR) scale and calculated as combined HRs and 95% confidence intervals (CIs). All statistical tests were two-sided.

RESULTS

The network meta-analysis compared 11 different surgical regimens that consisted of 13 and 17 direct comparisons between strategies for OS (34 trials; n = 23 587 patients) and DFS (32 trials; n = 22 552 patients), respectively. The values of surface under the cumulative ranking for OS and DFS after mastectomy (M)+radiotherapy (RT) were observed to be the largest. Breast-conserving surgery (BCS)+axillary node sampling+RT almost achieved the threshold for inferiority compared with the other surgical treatment arms and was statistically significantly associated with worse OS (HR = 0.51, 95% CI = 0.24 to 0.94; HR = 0.48, 95% CI = 0.22 to 0.92; HR = 0.51, 95% CI = 0.23 to 0.96). No statistically significant difference between BCS+sentinel lymph node biopsy (SLNB)+RT vs BCS+SLNB+intraoperative RT was observed in carrying out network meta-analysis (HR = 0.95, 95% CI = 0.64 to 1.36).

CONCLUSIONS

M+RT has the most favorable survival outcomes among the various surgical regimens for the treatment of early breast cancer patients. For patients who receive BCS, SNLB has more favorable outcomes than axillary node sampling. Intraoperative RT and postoperative RT have similar outcomes in patients who receive SLNB.

Meta-analytic comparison of randomized and nonrandomized studies of breast cancer surgery

BACKGROUND

Randomized controlled trials (RCTs) are thought to provide the most accurate estimation of "true" treatment effect. The relative quality of effect estimates derived from nonrandomized studies (nRCTs) remains unclear, particularly in surgery, where the obstacles to performing high-quality RCTs are compounded. We performed a meta-analysis of effect estimates of RCTs comparing surgical procedures for breast cancer relative to those of corresponding nRCTs.

METHODS

English-language RCTs of breast cancer treatment in human patients published from 2003 to 2008 were identified in MEDLINE, EMBASE and Cochrane databases. We identified nRCTs using the National Library of Medicine's "related articles" function and reference lists. Two reviewers conducted all steps of study selection. We included studies comparing 2 surgical arms for the treatment of breast cancer. Information on treatment efficacy estimates, expressed as relative risk (RR) for outcomes of interest in both the RCTs and nRCTs was extracted.

RESULTS

We identified 12 RCTs representing 10 topic/outcome combinations with comparable nRCTs. On visual inspection, 4 of 10 outcomes showed substantial differences in summary RR. The pooled RR estimates for RCTs versus nRCTs differed more than 2-fold in 2 of 10 outcomes and failed to demonstrate consistency of statistical differences in 3 of 10 cases. A statistically significant difference, as assessed by the z score, was not detected for any of the outcomes.

CONCLUSION

Randomized controlled trials comparing surgical procedures for breast cancer may demonstrate clinically relevant differences in effect estimates in 20%-40% of cases relative to those generated by nRCTs, depending on which metric is used.

Usefulness of intraoperative touch smear cytology in breast-conserving surgery

In breast-conserving surgery, positive margins are closely related to intramammary recurrence, but methods of assessing resection stumps during breast-conserving surgery have not been standardized. The present study investigated the usefulness of intraoperative touch smear cytology in our department. From 2005 to 2008, a total of 420 patients underwent breast cancer surgery. Subjects comprised 160 patients who underwent breast-conserving surgery and touch smear cytology. Results of the touch smear cytology were compared to those of the histological tissue analysis. Touch smear cytology displayed 70% sensitivity (14/20), 97.1% specificity (136/140) and a diagnostic accuracy of 93.8% (150/160). Six false-negative cases and 4 false-positive cases were identified. Of the 6 false-negatives, cancer cells were noted in the ductal component in 5 cases, and the degree of cancer cell atypia in the stump was low. Residual cancer cells were noted in the stump in 18 cases, and additional resection was performed in 16 cases. Cancer cells were identified histologically in the additionally resected tissue in 8 of these 16 cases (50%). The direction of positive cytology was towards the nipple in 16 cases, lateral tissue in 5 cases and contralateral nipple in 2 cases. A greater cancer cell volume, as assessed by touch smear cytology, tended to be associated with higher frequency of positive margins, as assessed by histological tissue analysis. Touch smear cytology is easy to perform, offering a very useful technique yielding comparable results to histological tissue analysis.

Clinical Significance of Multidetector-Row Computed Tomography in Breast Surgery

Several reports support the association of higher ipsilateral breast tumor recurrence rates with positive or intermediate margins compared with negative pathologic margins. Precise evaluation of tumor extension and adequate surgical margin are important factors affecting tumor recurrence after breast-conserving surgery (BCS). Many studies have reported the utility of magnetic resonance imaging (MRI) for diagnosing the tumor extension of breast cancer, but few have evaluated the utility of multidetector-row computed tomography (MDCT). The results of this study show the clinical significance of MDCT for detecting cancer extension and demonstrate the clinical role of MDCT in BCS. Subjects comprised 136 patients grouped into two categories based on whether or not tumor extension was evaluated with MDCT preoperatively. The positive surgical margin rate and breast conservation rate were analyzed in each group and the clinical role of MDCT in BCS was evaluated. Moreover, evaluation of intraductal extension was done both with MDCT and histologically, and computed tomography (CT)-pathologic correlations were examined retrospectively. Finally, the margin-positive cases were analyzed in relation to their clinical characteristics. Sensitivity, specificity, positive predictive value, and negative predictive value for detection of the intraductal component were 71.8%, 85.7%, 82.1%, and 76.9%, respectively. The positive surgical margin rate and conservation rate are 7.46% and 81.9%, respectively, for those who were diagnosed with MDCT preoperatively; their corresponding rates without MDCT were 16.67% and 67.9%. Most margin-positive patients have remarkable lymphatic space invasion. Positive surgical margins were often recognized toward the nipple. For diagnosing the intraductal extension, MDCT shows sufficient diagnosability. Moreover, MDCT can provide appropriate information for the determination of adequate surgical margins and contribute to increases in breast conservation rates.

Multidetector row computed tomography for diagnosing intraductal extension of breast carcinoma

OBJECTIVES

Several reports supported the association of higher ipsilateral breast tumor recurrence rates with positive or intermediate margins compared with negative pathologic margins. Precise evaluation of intraductal component and adequate surgical margin are important factors affecting the tumor recurrence after breast conserving surgery. Numerous studies have reported the utility of magnetic resonance imaging for diagnosing developing intraductal extension of breast cancer, but few have investigated multidetector-row computed tomography (MD-CT). The present study evaluated the clinical utility of MD-CT for detecting intraductal extension of breast carcinoma, and analyzed clinical parameters affecting the detection of intraductal extension under MD-CT.

METHODS

Subjects comprised 44 patients grouped into three categories according to degree of intraductal extension of the main tumor under MD-CT (Intraductal spread grade 1 approximately 3: IDS 1 approximately 3). Tumors were also categorized histopathologically (p-IDS 0 approximately 3), and CT-pathological correlations were examined retrospectively. Clinical parameters were evaluated to determine the affect on detection of intraductal components.

RESULTS

MD-CT detected 44 breast lesions (100%). Sensitivity for detection of intraductal component was 81.2%, specificity was 67.8%, and accuracy was 72.7%. Regarding extent of intraductal components, significant correlations were found between histopathological and MD-CT findings. A strong correlation was found in postmenopausal women between T2 tumor and high histological grade.

CONCLUSIONS

MD-CT findings of intraductal extension from breast carcinoma correlate with histological degree of intraductal extension, and MD-CT may be useful for preoperative assessment of breast-conserving surgery, particularly for postmenopausal women with histological high nuclear grade and T2 tumor.

Breast-conserving surgery has equivalent effect as mastectomy on stage I breast cancer prognosis only when followed by radiotherapy

BACKGROUND AND PURPOSE

Early-stage breast cancer is increasing and consequently the use of breast-conserving surgery (BCS). We examined the effect of mastectomy and BCS on overall and breast cancer survival in routine health care in Geneva, Switzerland.

PATIENTS AND METHODS

We included all stage I breast cancers treated by surgery (n=1046) recorded at the Geneva Cancer Registry between 1988 and 1999. The effect of treatment type was evaluated by Cox models, which accounted for confounders.

RESULTS

Overall, 780 (75%) women had BCS with radiotherapy, 57 (5%) BCS alone and 209 (20%) mastectomy. The overall 10-year survival was 86, 56, and 72%, respectively. The effect of BCS with radiotherapy was similar to that of mastectomy for both breast cancer mortality (adjusted hazard ratio (HR), 0.67; 95%CI, 0.31-1.38) and other causes of mortality (HR, 0.79; 95%CI, 0.49-1.28). Women with BCS alone had higher mortality from breast cancer (HR, 3.95; 95%CI, 1.59-9.84).

CONCLUSIONS

This retrospective study shows that BCS plus radiotherapy is the predominant treatment in routine practice for stage I breast cancer in Geneva, with the same effect on survival as mastectomy. In this data set the addition of radiotherapy to BCS substantially reduces mortality from breast cancer without increasing other causes of mortality after 10 years of follow-up.

Breast-conserving therapy versus modified radical mastectomy in the treatment of early breast cancer in Japan

BACKGROUND

Breast-conserving therapy has been widely utilized as a treatment option for women with early breast cancer. However, no randomized study comparing modified radical mastectomy and breast-conserving therapy has been conducted in Japan.

METHODS

Two hundred and twenty-eight Japanese women with early breast cancer enrolled in the Gunma Breast Conserving Therapy Study between 1991 and 1994 were examined to determine whether there is any difference in disease-free survival or overall survival between radical mastectomy and breast-conserving therapy. After informed consent was obtained, a total of 119 patients underwent breast-conserving therapy and 109 underwent mastectomy.

RESULTS

Mastectomy was a more frequently utilized treatment than breast-conserving therapy in patients with clinical stage II lesions, older age, larger tumor size or shorter distance between tumor and nipple. The mean follow-up period for all patients was 81 months (median 86 months). There was no significant difference in overall survival or disease-free survival between breast-conserving therapy and mastectomy even after adjusting for the clinical stage of the disease. A multivariate analysis of tumor size, lymph node status, estrogen receptor status and operation method using the Cox proportion hazard model confirmed that only lymph node status was an independent prognostic factor.

CONCLUSION

Breast-conserving therapy is comparable to modified radical mastectomy in overall survival and disease-free survival.