Surgical Pathology and the role of the Pathologist in cancer detection

16.OCT.09

by Dr. R Child – consultant Surgical Pathologist at the Milton Cato Memorial Hospital.

Surgical pathology is a hospital based speciality which has developed into a major branch of clinical medicine with the surgical pathologist now established as integral member of the team responsible for the care and management of the patient.{{more}}

In countries where surgical pathology is practiced, the law states that any tissue or fluid removed from the body should be sent to the pathologist. The major function of the pathologist therefore is to examine biopsies (the removal and examination, usually microscopic, of tissue from the living body, performed to establish precise diagnosis) as well as fluid or cells.

Before tissues or cells are examined microscopically by the pathologist, the samples have to undergo an elaborate process in order to produce a microscopic slide.

Specimens are sent to pathology laboratories from operating theatres, various clinics and consultation rooms.

Microscopic examination of the tissue may reveal one or more of the following: normal tissue; inflammation; reactive changes or a tumor. A tumor may be malignant (that is a cancer) or non-malignant (a benign lesion).

A surgical pathology report is then issued to the clinical consultant for further management of the patient depending on the diagnosis.

October being breast cancer awareness month makes it very appropriate, at this point in time, to elaborate a bit more on the procedures to which the breast can be subjected and the role the Pathologist plays in the diagnosis of this disease.

The sample sent by the surgeon may be: a needle biopsy; lumpectomy; micro/macrodochectomy; subareola wedge resection; segmental resection or a mastectomy specimen.

Biopsies are taken from the breast to investigate the nature of palpable breast lumps (fibroadenoma, fibrocystic change, fat necrosis, papilloma, carcinoma, etc), nipple bleeding and mammographic abnormalities. These biopsies are often preceded by fine needle aspiration. This involves sticking a needle (attached to a syringe) into the breast lump and aspirating small amount of tissue or cells. This is then examined microscopically.

A mastectomy is done in the case of a cancer (carcinoma or other types of malignant tumor).

All breast cancers should be evaluated for their receptor status. Evaluation of estrogen receptors (ERs) and or progesterone receptors (PgRs) status enables identification of women who are most likely to respond to hormone therapy.

Approximately two-thirds of breast cancers are hormone receptor positive. A higher percentage of estrogen receptor positive patients are found among older women. Estrogen positive breast cancer has a more favorable medium-term prognosis then estrogen receptor negative cancers. This is directly linked to administration of drugs such as tamoxifen.

Human epidermal growth factor receptor-2 (HER 2) is over expressed in 20-30% of human breast cancers.

HER-2 positive breast cancer is an aggressive form of the disease and correlates with poor prognosis, including high risk of recurrence, metastasis (spread from original site) and reduced overall survival.

Put simply, women who are found to have estrogen positive breast cancers can be administered tamoxifen which would give them a better outcome (i.e prolonged life). On the other hand, if the cancer is found to be HER-2 positive the patient would have an adverse outcome.

It is therefore necessary that receptor status be determined for all breast cancers in order to determine further management. Unfortunately, determination of these receptors cannot be done in St. Vincent- tissue has to be sent to laboratories overseas. This of course, being greatly restricted by fiscal considerations.

In summary, the principal aim of surgical pathology is obviously that of the accurate and clinically meaningful diagnosis of specimens taken from living patients. It involves more that just providing diagnostic labels. Treatment options and prognostic indicators are also provided, the final goal being cancer patients’ management using a team approach.