Use of laser capture microdissection allows detection of loss of heterozygosity in chromosome 9p in breast cancer.

The present study was designed to determine whether loss of heterozygosity (LOH) in the p arm of chromosome 9 in invasive ductal carcinoma of the breast is detected during the neoplastic progression of the disease. Using laser capture microdissection (LCM) epithelial cells were isolated from 14 invasive ductal carcinoma cases (IDC), ductal carcinomas in situ (DCIS), normal mammary lobules, skin and/or lymph nodes of paraffin embedded tissue sections. LOH analysis of chromosome 9p was performed utilizing the microsatellite markers D9S199, D9S157, D9S171, D9S265 and D9S270. The highest frequency of LOH was observed in invasive ductal carcinomas, which reached a maximum at the 9p22-23 chromosomal location (D9S157). In addition, DCIS lesions presented a high frequency of LOH in 9p22-23 (D9S157), followed by 9p21 (D9S171), D9S199 and D9S265, which were similar in frequency to those observed in IDC. A novel finding was the intralesional heterogeneity in LOH within the same DCIS or IDC case. This is an indication that clones of cells that differ in genetic composition coexist in the same lesion. Notably, phenotypically normal breast tissues adjacent to IDC or DCIS exhibited LOH at D9S157 and/or D9S171. Together, these data indicate that LOH of chromosome arm 9p occurs very early in the progression of cancer and that different clones of cells co-exist within a single tumor.

DNA content and cell number determination in microdissected samples of breast carcinoma in situ.

Paraffin-embedded tissue (PET) is the specimen of choice for the histopathological diagnosis of cancer. PET has become a valuable resource for correlating cellular phenotype and genotype in microdissected lesions. A definitive improvement in this field has been the development of infra-red laser capture microdissection (LCM), which yields homogeneous populations of cells for DNA extraction and in vitro amplification by polymerase chain reaction (PCR). We report here a photographic and fluorescent technique for determining the number of nuclei and concentration of DNA obtained respectively by laser capture microdissection from paraffin-embedded breast cancer tissue. Breast biopsies containing carcinoma in situ were serially sectioned, mounted on plain glass slides and tumor cells were microdissected using a laser capture microscope. The DNA was extracted in digestion buffer and used directly as a template for PCR. In our protocols, each capture contained 21+/-5.4 nuclei with a DNA concentration of 115+/-5.3 pg. Also, a linear relationship was found between number of captures and DNA content (R2=0.9995). These results represent a novel contribution for a more precise correlation between phenotypic and genotypic diversity in cancer cells studied from microdissected paraffin-embedded tissue.

Surgeons and the spirit: a study on the relationship of religiosity to clinical practice.

This study aimed to identify the religious practices and beliefs of surgeons and the relationship between surgeons' locus of control and religiosity. Thirty-five surgeons completed a survey that included items from the Duke University Religion Index, the Salesian Center Intrinsic Religiosity Scale for Clinicians, and Rotter's Locus of Control Scale. Over 68% of sampled surgeons affirmed that their religious beliefs play a part in their practice, 47% attend religious services at least weekly, and 44% pray daily. There was no correlation between locus of control and religiosity. These results challenge the myth of the egocentric, agnostic surgeon.