Breast cancer: The new biology in conflict with the old dogma

Let us summarize the pathophysiology of breast cancer according to the new biology. One or more unknown factors, (eg, hormonal, hereditary) lead to the development of proliferative changes in the glandular tissue of the breast. These changes are premalignant and render the patient at higher risk for breast cancer. Among those who show proliferative change, a smaller group (less than 4% of women who have breast biopsies and about 12% of those with proliferative change) develop atypical changes and are at particularly high risk.The explanation for these histologic events may be as follows: the etiologic agents of breast cancer produce a series of mutations that may activate oncogenes necessary for malignant transformation. Activation of these genes may produce in sequence proliferative growth, proliferative growth with atypia, in situ carcinoma, low grade invasive intraductal carcinoma, and subsequently overt clinical breast cancer. At some point this sequence becomes autonomous, ie, no longer dependent on the original etiologic factors. The cancer enters a progression phase in which its cells develop the capacity to invade blood vessels, survive in metastatic sites, lose their estrogen receptors, accelerate their growth rate, and develop resistance to chemotherapeutic agents. Not all precancerous lesions or in situ cancers evolve into clinical disease. Autopsy studies on women with no evidence of breast cancer show that 20% have invasive or in situ cancer of the breast.²⁸By the time we interrupt this chain with detection of a palpable or mammographically visible breast mass, it may be too late to completely reverse the process. Early detection may help some. Adjuvant chemotherapy may contribute a bit more. In view of the recent histologic data, it might be desirable to investigate the possibility of identifying women at special high risk by means of biopsy. Such women could then be given either special diagnostic attention or considered for prophylactic mastectomy. One might speculate that women at special high risk of breast cancer might be protected by prophylactic radiation of both breasts. Such a procedure might be far less cosmetically unsatisfactory than prophylactic mastectomy.With our better understanding of cancer biology, we may be able to develop therapy that will substantially improve cure rates. We need new clinical trials designed to test various aspects of the new biology of cancer. Dupont and Page have identified a very high risk group: can we devise acceptable and effective prophylaxis for this group? Adjuvant chemotherapy seems to modestly improve survival: can we confirm this and increase the salvage with better regimens? According to the new biology, certain steps in cancer progression can be predicted: can we develop therapeutic strategies that take advantage of this theoretic possibility? These and other questions demand attention in future studies.     

Assessment of the acutely ill cancer patient

The process of assessing the acutely ill cancer patient must be organized and systematic. The framework outlined in this article provides a method that ensures complete and consistent data collection. These data can then be utilized to formulate specific patient problems and diagnostic statements and to form the basis for specific nursing actions.     

Ectopic hormonal production: Nursing implications

Ectopic hormone production describes a classification of syndromes in which hormone-like substances are produced not by normal parent tissue but by tumor. These ectopically produced hormones are probably the result of gene derepression that corresponds with the neoplastic process. Since their elaboration is controlled by tumor, they do not respond to normal negative feedback mechanisms. The resultant elevation of hormone manifests in clinical and/or laboratory findings.

Medical care is aimed at treating the underlying tumor and controlling the fluid and electrolyte problems. Nursing care emphasizes increased observation of physical changes; promoting return of normal body homeostasis; providing physical and emotional support; and teaching the patient and family to recognize the syndromes and how to care for the patient themselves.     

Disseminated intravascular coagulopathy and nursing implications

The diagnosis of DIC depends upon a high index of suspicion in the appropriate clinical setting. Laboratory studies (platelet count, PT, PTT, fibrinogen, and the measurement of fibrin split products), are used to confirm the diagnosis, and treatment is directed at the underlying illness that has caused DIC. It may be necessary to give component therapy and heparin to control the bleeding and thrombotic manifestations of DIC. Sequential clotting studies are necessary, and resolution of DIC is measured by bleeding cessation, normal clotting studies, and lack of progression of thrombosis. ³⁹ The nursing approach to DIC has recently been reviewed by Rooney and Haviley.⁴⁰ Total nursing care given to these patients incorporates a wealth of nursing skills including identification of patients at risk, accurate and early assessment of signs and symptoms, prompt and appropriate follow-up for nursing interventions, careful teaching, and emotional supportive care.     

Simultaneous isothermal determination of diphenylhydantoin and phenobarbital serum levels by gas-liquid chromatography following flash-heater hexylation.

A rapid, accurate, precise, and sensitive procedure for the simultaneous determination of diphenylhydantoin and phenobarbital under isothermal conditions involves on-column hexylation of the compounds. After extraction of serum samples, the evaporated residues are dissolved in tetrahexylammonium hydroxide. An aliquot of the resulting solution is introduced directly into a gas chromatograph where conversion to hexyl derivatives and subsequent separation takes place. The hexylated derivatives are identified by their retention times relative to appropriate internal standards. Concentrations are obtained from standard curves plotting relative peak height versus concentration of drug.