The perfect tumor marker would be one that was produced solely by a tumor and secreted in measurable amounts into body fluids, it should be present only in the presence of cancer, it should identify cancer before it has spread beyond a localized site (i.e., be useful in screening), its quantitative amount in bodily fluids should reflect the bulk of tumor, and the level of the marker should reflect responses to treatment and progressive disease. Unfortunately, no such marker currently exists, although a number of useful but imperfect markers are available. The predominant contemporary markers are discussed here by chemical class, as follows: glycoprotein markers, including carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), beta-human chorionic gonadotropin (beta-hCG), and prostate specific antigen (PSA); mucinous glycoproteins, including CA 15-3, CA 19-9, mucinous-like cancer antigen and associated antigens, and CA 125; enzymes, including prostatic acid phosphatase (PAP), neuron specific enolase (NSE), lactic acid dehydrogenase (LDH), and placental alkaline phosphatase (PLAP); hormones and related endocrine molecules, including calcitonin, thyroglobulin, and catecholamines; and, molecules of the immune system, including immunoglobulins and beta-2-microglobulin. The biologic properties of each group of tumor markers are discussed, along with our assessment of their role in clinical medicine today.

Biomarkers, Tumor↗

PubMedDate not supplied

Non-small cell lung cancer.

Lung cancer stands as the most important malignant neoplasm in the United States because of its high prevalence, increasing incidence, high rate of mortality, and great potential for prevention through the control of cigarette smoking. The World Health Organization (WHO) classification of lung cancer identifies four major types: squamous cell carcinoma, adenocarcinoma, large cell carcinoma, and small cell carcinoma. These tumors are commonly divided into two groups based on differences in their biology and treatment: small cell (SCLC) and non-small cell carcinomas (NSCLC). This review analyzes NSCLC with a strong emphasis on the practical aspects of treatment. We give recommendations about smoking cessation and early diagnosis through screening of high-risk individuals. We review contemporary diagnostic and staging techniques in the context of the new international TNM system of staging. Subsequent discussions of treatment are based on this new staging system. We stress the pivotal role of surgery for the management of local disease, and in addition present the potential contributions of newer radiation therapy techniques. We examine chemotherapy in detail, including a review of the comparative activity of the available cytotoxic agents against NSCLC, the relative contribution of combination chemotherapy, and the role of surgical adjuvant treatment with either chemotherapy or immunotherapy. We advise that patients with NSCLC be treated under the aegis of modern clinical trials of new therapy whenever possible. When this is not possible, we recommend an individualized approach based on such factors as the patient's age, general state of health, cardiopulmonary status, psychosocial status, and personal system of values.

Aged↗

PubMedDate not supplied

Metastasis of unknown origin.

Metastasis of unknown origin (MUO) constitutes between 5% and 10% of all noncutaneous cancers. An MUO is defined as a metastatic tumor for which the site of origin is not suggested by thorough history, physical examination, chest x-ray studies, routine blood and urine studies, and histologic evaluation. Two major groups of MUO can be defined: MUO to lymph nodes only (N1-3), and MUO to visceral sites. The prognosis may be quite good for patients with MUO limited to lymph nodes in the mid to high cervical, axillary, and groin areas. However, MUO in other lymph node areas is far more serious, with the possible exception of that in patients with a new syndrome, i.e., "advanced poorly differentiated carcinoma of unknown primary origin." There is some suggestion that these patients may respond to cisplatin-based combination chemotherapy. Patients with MUO to visceral sites have a poor prognosis. However, metastases from some primary tumors are sensitive to chemotherapy and a limited search for these tumors should be undertaken. These tumors include leukemia-lymphoma, germ cell tumors, small cell carcinoma of the lung, adenocarcinomas of the breast, ovary, endometrium, thyroid, or prostate, and possibly adrenal carcinoma. We start by reviewing the biochemical events of metastasis that may be targets for therapy. The importance of a correct tissue diagnosis is then considered, including the role of standard histochemistry, electron microscopy, enzyme histochemistry, and immunohistochemistry. The relatively limited value of radiologic tests in localizing the primary site of origin of the tumor is emphasized, as well as the limited role of currently available biomarkers. We conclude by discussing the treatment of each of the subtypes of MUO.

Adenocarcinoma↗