Early detection of breast cancer through population-based mammographic screening in Asian women: a comparison study between screen-detected and symptomatic breast cancers.

The first nation-wide mammographic screening program in Asia, BreastScreen Singapore (BSS), was launched in Singapore in January 2002. This study compared the presentation and results of screen-detected breast cancers with symptomatic breast cancers in two affiliated high-volume institutions, one of which was an assessment centre for BSS. The medical records of patients diagnosed with primary breast cancer at the Department of General Surgery, Singapore General Hospital and the Department of Surgical Oncology, National Cancer Centre, Singapore, during the period January 2002 to December 2003 were reviewed. Clinical and pathological comparisons were made between screen-detected lesions and symptomatic lesions. Of a total of 767 cases, 640 (83.4%) were invasive carcinomas and 127 (16.6%) were ductal carcinoma in-situ (DCIS) lesions. Only 13.4% of them were screen-detected. Compared to symptomatic cancers, screen-detected lesions were of smaller size (median size 18 versus 23 mm), a lower stage (stages 0-2, 95 versus 83.2%) and histologic grade (grade 1-2, 71 versus 60%), with a higher incidence of DCIS (31.0 versus 14.3%) and had higher rates of breast conservation (45.6 versus 28.2%) (all p-values <0.05). By multivariate analysis, tumor palpability, tumor size >20 mm, nodal involvement, cerbB2 overexpression, and advanced disease stage were independent poor prognostic factors for disease-free survival, whereas nodal involvement, advanced disease, and recurrence predicted poor cancer-specific survival. However, there was no statistically significant difference in disease-free survival or cancer-specific survival between the two groups at a median follow-up of 38 months. Screening mammography has allowed the detection of smaller and hence oncologically more favorable lesions in Asian women. Although no significant survival benefit was demonstrated in our study, a longer period of follow-up is essential before the benefit of mortality reduction, as a result of mammography screening becomes evident in our population.

Treatment for ductal carcinoma in situ in an Asian population: outcome and prognostic factors.

BACKGROUND: Breast cancer is the most common cancer among Singapore women and ductal carcinoma in situ (DCIS) is believed to be the precursor of most invasive breast cancers. The incidence of DCIS has increased dramatically with mammographic screening, but its treatment remains controversial. Further, results of treatment for DCIS in Asians, and in particular Singapore women, are lacking. We review our institution's results treating a predominantly Chinese population with DCIS of the breast before the introduction of mammographic screening and aim to determine treatment outcomes and identify prognostic factors for disease recurrence. METHODS: Between January 1994 and December 2000, 170 consecutive patients with DCIS were treated at our institution. One hundred and three (60.5%) were managed with breast conservation (17 with local wide excision alone and 86 with adjuvant irradiation following wide excision) whereas 67 (39.4%) underwent mastectomy. Of those who underwent wide local excision, 56 (54.3%) underwent re-excision for margin clearance. Overall, the axilla was surgically staged in 47 (27.6%) and no nodal involvement was found in all cases. Pathological specimens were reviewed by one of the authors. Median follow up was 86 months (range 4-151 months). RESULTS: Sixty-two patients (36%) were asymptomatic at presentation whereas most (64%) presented with clinical symptoms; out of these more than half (54%) presented with a palpable lump. The median size of tumours was 13 mm (range 1.5-90 mm). Patients who underwent breast conservation surgery had oncologically more favourable lesions - with a significantly higher incidence of smaller and non-palpable lesions and lesions of lower nuclear grade. However, there was also a significantly higher incidence of local recurrence in this group. At the end of follow up, there were 12 patients (7.1%) who developed local recurrence and 8 patients (4.7%) developed contralateral disease. The crude incidence of all breast events (including both local failure and contralateral events) at 5 years was 5.6%. Median time to the development of any breast event (local recurrence or contralateral disease) was 60 months (range 12-120 months). The cumulative 5-year recurrence-free survival for patients who underwent breast conservation surgery was 94%. Factors influencing local recurrence rate were close or involved margins (

Outcomes for abdominoperineal resections are not worse than those of anterior resections.

PURPOSE: Local recurrence and cure rates following abdominoperineal resections have been reported to be much worse than sphincter-preserving anterior resections. We compared the oncologic outcomes of patients treated by abdominoperineal resections with those following sphincter-preserving anterior resections. METHODS: The medical records of patients who underwent radical rectal resection for rectal carcinoma at the Colorectal Surgery Department, Singapore General Hospital, during the period from April 1989 to April 2002 were reviewed. A total of 791 cases were studied. Operative procedures were classified as either abdominoperineal resections or anterior resections with either straight or pouch anastomosis. Total mesorectal excision was routinely performed for carcinomas of the lower middle and lower third of the rectum. Sentinel events, including local and systemic recurrences or morbidity and mortality, were tracked prospectively. RESULTS: There were a total of 93 abdominoperineal resections (12.1 percent), 547 anterior resections with straight anastomoses (71 percent), and 130 anterior resections with pouch anastomoses (16.9 percent). Postoperative mortality was 2.6 percent and postoperative morbidity was 13.6 percent with an overall anastomotic leakage rate of 2.5 percent. The cumulative five-year local recurrence rate was 5.4 percent for abdominoperineal resections, 3.6 percent for anterior resections with straight anastomoses, and 3.8 percent for anterior resections with pouch anastomoses (P = 0.73 by log-rank test). The median time to local recurrence also did not differ significantly between the different procedures (abdominoperineal resections, 17 months, anterior resections with straight anastomoses, 18 months, anterior resections with pouch anastomoses, 13 months). Independent predictors for local recurrence included advanced tumor stage, tumor depth, and poorly differentiated tumors. The five-year cancer-specific survival was 70 percent. The type of anastomosis did not influence disease-free survival with median disease-free survival for patients who underwent abdominoperineal resections being 100 months, survival of anterior resections with straight anastomoses being 135 months, and survival of anterior resections with pouch anastomoses being 121 months (P = 0.33 by log-rank test). The independent factors for poor survival were age greater than 65 years, advanced tumor stage, tumor depth, and poorly differentiated tumors. CONCLUSION: Both abdominoperineal resections and sphincter-preserving anterior resections can be performed safely with low morbidity and mortality in a specialized high-volume hospital unit without compromising oncologic outcomes. With appreciation of the anatomic relations in total mesorectal excision and standardized consistent surgical technique, the oncologic outcomes of patients treated by abdominoperineal resections are not worse than those treated by sphincter-preserving anterior resections.

Prognostic significance of peritoneal lavage cytology in gastric cancer in Singapore.

BACKGROUND: Peritoneal lavage cytology has been included as part of the staging process in the 13th edition of the Japanese Classification of Gastric Cancer. However, this procedure has neither been studied nor established in our population. We aimed to evaluate its prognostic relevance among our patients with gastric cancer. METHODS: A total of 142 consecutive patients with gastric carcinoma were recruited prospectively. All had histologically proven gastric carcinomas and had undergone laparotomy and intraoperative peritoneal lavage for cytological examination at Singapore General Hospital. The fluid recovered was centrifuged and stained by the Papanicolau method. All patients were followed up with endpoints of cancer recurrence and mortality. RESULTS: There were 91 men and 51 women; 36 patients (25.4%) had positive peritoneal lavage. Patients with advanced macroscopic features, presence of vascular invasion, nodal involvement, advanced depth of tumor invasion and metastatic disease tended to have positive lavage, by univariate logistic regression analysis. Despite curative resections, patients with positive cytology had a more dismal disease-free survival (mean, 27 months vs 53 months; P < 0.0001 by log rank test) and higher recurrence rate (54.5% vs 19.3%; P = 0.007 by log rank test). There was also a trend towards earlier recurrences (median, 8 months vs 11 months; P = 0.37). By multivariate Cox regression stepwise analysis, advanced depth of tumor invasion and positive lavage cytology were found to be independent poor prognostic factors for disease-free survival. CONCLUSION: Positive peritoneal lavage cytology correlated well with advanced features of gastric cancer. It is an independent poor prognostic factor and the procedure should be routinely performed. Integration of lavage status into our current staging systems may serve as a guide for adjuvant therapeutic options to improve the survival of gastric cancer in our population.