SURGICAL ONCOLOGY AND TUMOR MARKERS

SURGICAL ONCOLOGY AND TUMOR MARKERS Cancer is a diverse group of diseases collectively characterized by an unregulated proliferation of undifferentiated cells that invade local tissue and may spread or metastasize to other parts of the body, so Cancer cells are psychopaths. They have no respect for the rights of other cells.

EPIDEMIOLOGY One in four deaths in the United States is due to cancer, second only to deaths from heart disease. In 2011, approximately 1,596,670 new cancer cases and 571,950 cancer deaths were projected in the United States. In children between the ages of 1 and 14 years, cancer is second only to deaths by accidents

CANCER BIOLOGY malignant transformation is the result of cells acquiring four functional capabilities: (1) the ability for self-suffi cient growth (2) an insensitivity to antigrowth signals, (resist signals that inhibit growth) (3) the ability to evade apoptosis (programmed cell death), and (4) the capacity of limitless replication.

Two other functional capabilities acquired by cancer cells include sustained angiogenesis and tissue invasion, but these changes occur not only within the cancer cell itself but also in its interaction and relationship with other elements.

The following factors may suggest the presence of a hereditary cancer The following factors may suggest the presence of a hereditary cancer. 1. Tumor development at a much younger age than usual 2. Presence of bilateral disease 3. Presence of multiple primary malignancies 4. Presentation of a cancer in the less affected sex (e.g., male breast cancer) 5. Clustering of the same cancer type in relatives 6. Occurrence of cancer in association with other conditions such as mental retardation or pathognomonic skin lesions

TUMOR MARKERS Prognostic and Predictive Tissue Markers Tumor markers are substances that can be detected in higher than normal amounts in the serum, urine, or tissues of patients with certain types of cancer. Tumor markers are produced either by the cancer cells themselves or by the body in a response to the cancer.

the term prognostic marker generally is used to describe molecular markers that predict disease-free survival, disease-specific survival, and overall survival, For example, ideal prognostic tumor markers would be able to help determine which patients with node-negative breast cancer are at higher risk of relapse so that adjuvant systemic therapy could be given only to that group.

Predictive markers are markers that can prospectively identify patients who will benefit from a certain therapy. For example in breast cancer, estrogen receptor (ER) and HER2 assessment can identify patients who can benefit from antiestrogen therapies (e.g., tamoxifen) and anti-HER2 targeted therapies (e.g., trastuzumab), respectively

Serum Markers Serum markers are under active investigation because they may allow early diagnosis of a new cancer or may be used to follow cancer response to therapy or monitor for recurrence.

when a tumor marker is used to monitor recurrence, it is important to be certain that the level of the tumor marker was elevated before primary therapy. Moreover, tumor marker levels can be elevated in benign conditions.

Many tumor markers are not specific for a certain type of cancer and can be elevated with more than one type of tumor.

Prostate-Specific Antigen Prostate-Specific Antigen. Prostate-specific antigen (PSA) is an androgen-regulated serine protease produced by the prostate epithelium. PSA is normally present in low concentrations in the blood of all adult males. PSA levels may be elevated in the blood of men with benign prostate conditions such as prostatitis and benign prostatic hyperplasia, as well as in men with prostate cancer.

PSA levels have been shown to be useful in evaluating the effectiveness of prostate cancer treatment and monitoring for recurrence after therapy. In monitoring for recurrence, a trend of increasing levels is considered more significant than a single absolute elevated value.

Carcinoembryonic Antigen Carcinoembryonic Antigen. Carcinoembryonic antigen (CEA) is a glycoprotein found in the embryonic endodermal epithelium. Elevated CEA levels have been detected in patients with primary colorectal cancer as well as in patients with breast, lung, ovarian, prostate, liver, and pancreatic cancer

Levels of CEA also may be elevated in benign conditions, including diverticulitis, peptic ulcer disease, bronchitis, liver abscess, and alcoholic cirrhosis, especially in smokers and in elderly persons.

CEA measurement is most commonly used in the management of colorectal cancer. However, the appropriate use of CEA testing in patients with colorectal cancer has been debated. Use of CEA level as a screening test for colorectal cancer is not recommended

CEA levels may be useful if obtained preoperatively and postoperatively in patients with a diagnosis of colorectal cancer. Preoperative elevation of CEA level is an indicator of poor prognosis.

Alpha-Fetoprotein. Alpha-fetoprotein (AFP) is a glycoprotein normally produced by a developing fetus. AFP levels decrease soon after birth in healthy adults. An elevated level of AFP suggests the presence of either primary liver cancer or a germ cell tumor of the ovary or testicle.

Benign conditions that can cause elevations of AFP include cirrhosis, hepatic necrosis, acute hepatitis, chronic active hepatitis, , and pregnancy

The sensitivity of an elevated AFP level for detecting HCC is approximately 60%. AFP is considered to be sensitive and specific enough to be used for screening for HCC in high risk population. With improvement technology a larger proportion of patient diagnosed with HCC are now AFP Seronegative.

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