Benita Kiat Tee Tan

Sarcoma of the breast: an update on a rare entity

Breast sarcoma is a rare condition. It consists of a heterogeneous group of non-epithelial tumours arising from the mesenchymal tissue of the breast. It has a distinctly different natural history, treatment response and prognosis as compared with carcinoma of the breast. A different diagnostic approach and treatment strategy have to be defined for this group of tumours. Due to its rarity, the current understanding on breast sarcoma is limited and is mostly based on small retrospective case series or case reports. Hence, the management generally follows the algorithms derived from randomised control trials of soft tissue sarcomas in the extremities and chest wall. Through this review, we discuss the results of major retrospective studies on breast sarcomas including data on epidemiology, aetiology, diagnostic approach, treatment strategies and outcomes of this challenging and potentially aggressive condition.

False negative rate for intraoperative sentinel lymph node frozen section in patients with breast cancer: a retrospective analysis of patients in a single Asian institution

Background and objective Intraoperative frozen section of the sentinel lymph node (SLN) in clinically node negative breast cancer patients detects metastatic disease and enables axillary lymph node dissection to be performed in the same operative setting. Internationally, the false negative rate (FNR) for SLN biopsy ranges from 5.5% to 43%. The size of SLN metastasis has been identified as a key factor affecting FNR. We review our institutional experience on the accuracy of intraoperative SLN biopsy. Methods Data were collected retrospectively from patients undergoing SLN biopsy performed at Singapore General Hospital. The SLN was identified using blue dye, radioisotope or both. Frozen section was performed intraoperatively. When SLN was positive for metastasis on frozen section, completion axillary clearance was performed. False negative cases were defined as patients in whom a negative frozen section result was obtained, whose final permanent paraffin section was positive. We determined the FNR of SLN frozen section and evaluated the factors associated with it. Results A total of 2202 SLN biopsies were performed between January 2005 and June 2012. There were 89 false negative cases, of which there were 23 (25.8%) cases of isolated tumour cells (ITCs), 49 (55.1%) cases of micrometastasis, and 17 (19.1%) cases of macrometastasis. The overall FNR was 13.5%. FNR was 79.3% in ITCs, 59.8% in micrometastasis, and 3.1% in macrometastatic disease. Non-ductal histological subtype, absence of lymphovascular invasion and the size of SLN metastasis were identified as significant independent factors associated with a higher FNR. Conclusions FNRin our institution is acceptable when compared to other large centres. Failure to detect metastasis in frozen section in more than half of our patients was due to ITCs and micrometastasis.

Predicting the likelihood of additional lymph node metastasis in sentinel lymph node positive breast cancer: validation of the Memorial Sloan-Kettering Cancer Centre (MSKCC) nomogram

Aim To identify important clinicopathological parameters that are most helpful in predicting additional non-sentinel lymph node (SLN) metastasis among patients with a positive SLN biopsy in the Singapore breast cancer population. Methods A total of 1409 patients who underwent SLN biopsy were reviewed over a 5 year period from July 2004 to October 2009. A Singapore General Hospital (SGH) nomogram was developed from predictors in the Memorial Sloan-Kettering Cancer Centre (MSKCC) nomogram using 266 patients with primary invasive breast cancer and a positive SLN biopsy who subsequently had an axillary lymph node dissection. The SGH nomogram was calibrated using bootstrapped data, while the MSKCC nomogram was calibrated using SGH data. The performance of these two nomograms was compared with the calculation of the area under the receiver–operator characteristics curve and adequacy indices. Results The MSKCC nomogram achieved an area under the curve (AUC) of 0.716 (range 0.653–0.779) in our study population, while the SGH nomogram, which used only three pathological parameters, lymphovascular invasion, number of positive and negative SLN biopsies, achieved an AUC of 0.750 (range 0.691–0.808). The SGH nomogram with a higher adequacy index (0.969) provided better estimates compared with the MSKCC nomogram (0.689). Conclusions The use of the MSKCC nomogram was validated in our local patient population. The SGH nomogram showed promise to be equally, if not, more predictive as a model in our own population, while using only three pathological parameters.

Assessment of suitability of the one step nucleic acid amplification (OSNA) assay as an intraoperative procedure for detection of metastasis in sentinel lymph nodes of breast cancer

Aim We aimed to assess the one step nucleic acid amplification (OSNA) assay as an intraoperative method in comparison with frozen sections (FS) for detection of metastasis in sentinel lymph nodes (SLNs) of breast cancer. Method 100 SLNs from patients with breast carcinoma were enrolled within a 3-month period. Alternate 2 mm node slices were subjected to routine FS, and later to permanent histology, and the rest for automated molecular detection of CK19 mRNA using OSNA. FS and OSNA findings were compared with permanent histology results. Difference in turnaround time was also noted. Results With permanent histology as gold standard, OSNA was discrepant in 8 of 98 (3 false negative, 5 false positive) included SLNs whereas FS had 2 false negative cases. FS had higher sensitivity (89%, p=<0.001), specificity (100%, p=0.001) and concordance rate (98%) than OSNA (83%, 94% and 92%, respectively). FS showed almost perfect agreement (κ=0.929) whereas OSNA showed substantial agreement (κ=0.740) when compared with permanent histology. OSNA turnaround time was twice longer (mean of 47.7 min) than FS. Conclusions Automation of SLN assessment using OSNA is a potentially useful intraoperative diagnostic tool with acceptable accuracy. Discordant findings in this study may be due to sampling allocation. Since OSNA is more time-consuming, its practical advantage over routine FS requires further study in view of current technical workflow considerations.

Trends in Post‐Mastectomy Reconstruction in an Asian Population: A 12‐Year Institutional Review

Post‐mastectomy breast reconstruction is an integral component of breast cancer treatment. It is often perceived that women in Asian countries have a lower rate of post‐mastectomy reconstruction than Western populations. This study describes trends in timing and types of breast reconstruction performed in the largest healthcare provider in Singapore, over a period of 12 years. It also reports on the oncological outcomes and surgical safety. A retrospective review of all patients who underwent post‐mastectomy reconstruction from January 2001 to December 2012 at the National Cancer Centre Singapore and Singapore General Hospital was performed. Six hundred and twenty post‐mastectomy reconstructions were performed in 579 patients. The proportion of reconstructions increased from 4% in 2001 to 18% in 2012. Younger patients (<50 years old) and those with early stage cancer were more likely to undergo reconstruction. Immediate breast reconstruction was favored by more than 90% of patients. Postoperatively, 9% developed acute surgical complications that were treated surgically; 6% had additional surgery for late complications. Only 4% had delay of adjuvant chemotherapy. At median follow‐up of 63 months (range 3–166), loco‐regional recurrence was 4%, and distant metastases 8%. Post‐mastectomy reconstruction for breast cancer is increasingly performed in our institution. Both younger age and lower stage disease were associated with choice for reconstruction in our study. Low rates of delay to adjuvant therapy were noted, and it may safely be offered to suitable women undergoing mastectomy.

Breast carcinoma and phyllodes tumour: a case series

Malignant transformation of the epithelial component of phyllodes tumours (PT) is rare and only reported in literature as sporadic cases of carcinoma associated with PTs. We report the clinicopathological characteristics of in situ and invasive carcinoma coexisting with PT in 10 patients treated in our institution over an 11-year period from 1992 to 2012. Ten patients with coexisting PT and in situ or invasive carcinoma were identified from our records. Six had carcinoma found within the PT. All were female with a median age of 47 (43–72) years. One patient had a history of PT in the same breast while another had a history of PT in the same breast as well as invasive ductal carcinoma in the contralateral breast. The rest did not have any risk factors of breast cancer. Five patients had a preoperative core needle biopsy performed with the report of a fibroepithelial lesion. The rest of the patients had surgery upfront for their breast masses. Two patients who had ER/PR positive invasive carcinoma received adjuvant hormonal therapy. Patients were followed up for a mean of 3.6 years (9 months–10 years) and all patients were alive and recurrence free. PT associated with carcinoma is rare, and we present a series of cases that add to the limited current literature. It is often difficult to detect the presence of the carcinomatous component preoperatively. Hence, close examination of resected PT specimens must be carried out to allow prompt detection of any associated carcinomas, however rare, such that adequate treatment can be given.

Immediate breast reconstruction following nipple-sparing mastectomy in an Asian population: Aesthetic outcomes and mitigating nipple-areolar complex necrosis

Background Nipple-sparing mastectomies (NSMs) are increasingly performed to obtain the best aesthetic and psychological outcomes in breast cancer treatment. However, merely preserving the nipple-areolar complex (NAC) does not guarantee a good outcome. Darkly pigmented NACs and a tendency for poor scarring outcomes are particular challenges when treating Asian patients. Herein, we review the reconstructive outcomes following NSM at Singapore General Hospital. Methods All breasts reconstructed following NSM over an 11-year period from 2005 to 2015 were reviewed. Information was collected from the patients’ records on mastectomy indications, operative details, and complications. Patient satisfaction, breast sensation, and aesthetic outcomes were evaluated in 15 patients. Sensation was quantified using the Semmes-Weinstein monofilament test. Results A total of 142 NSMs were performed in 133 patients for breast cancer (n=122, 85.9%) or risk reduction (n=20, 14.1%). Of the procedures, 114 (80.2%) were autologous reconstructions, while 27 (19.0%) were reconstructions with implants. Complications occurred in 28 breasts (19.7%), with the most common complication being NAC necrosis, which occurred in 17 breasts (12.0%). Four breasts (2.8%) had total NAC necrosis. The overall mean patient satisfaction score was 3.0 (good). The sensation scores were significantly diminished in the skin envelope, areola, and nipple of breasts that had undergone NSM compared to non-operated breasts (P<0.05). Half of the subset of 15 patients in whom aesthetic outcomes were evaluated had reduced nipple projection. Conclusions Immediate reconstruction after NSM was performed with a low complication rate in this series, predominantly through autologous reconstruction. Patients should be informed of potential drawbacks, including NAC necrosis, reduced nipple projection, and diminished sensation.

P345 Perioperative outcomes of therapeutic breast surgery in the elderly

Dear Editor, Female Singaporeans currently have a life expectancy of 84.5 years1 and a lifetime risk of 6.5% of developing breast cancer.2 It is estimated that by the year 2050, 11.2% of the population will be aged more than 80 years.3 One in 16 women will develop breast cancer by the age of 80, and there will potentially be 1500 cases of newly diagnosed breast cancer among octogenarians each year. Surgery is curative in early breast cancer and various centres have reported no difference in the cancer specifi c survival rates of the elderly age group compared to their younger counterparts, 5 to 10 years after surgery for breast cancer.4,5 Surgery is also indicated in advanced breast cancer as a form of palliation in patients with fungating and bleeding tumours. Despite its therapeutic role, Lavelle et al6 found that the proportion of older women receiving surgery fell with increasing comorbidity and many clinicians still do not discuss surgical options with elderly patients. We wanted to objectively report the postsurgical mortality and morbidity of the very elderly, aged above 80 years in our institution. We also hoped to identify risk factors that may predict for a poorer outcome. To our knowledge, this is the fi rst study in an Asian population.