Biologic variations of tumors

Seminar in breast self-examination for female medical students integrated into a human gross anatomy course

A breast self-examination (BSE) seminar for first-year female medical students is presented and a single-gender approach for other subjects in the medical curriculum is discussed. In 1999 a small group seminar on BSE was offered at the Hannover Medical School to female medical students as part of their curriculum in human gross anatomy. An evaluation questionnaire was answered by 94 students (87% of participants). Frequencies of answers to two open questions were used as indicators of: 1) the acceptance of a single-gender course and 2) an increased awareness of breast cancer prevention. A linear regression analysis was carried out to identify the most important predictors for the global course evaluation and a heightened interest in breast cancer prevention. The mean global rating of the seminar was 13.8 (minimum: 1 point; maximum: 15 points). Factors that significantly influenced the global rating were the course atmosphere, the teacher's enthusiasm, and the professional interest of the students. An increased concern for breast cancer prevention was significantly dependent on the professional interest and the self-awareness of the women. The results suggest that there is a need for single-gender seminars in academic medicine and that instruction of female students in BSE is an ideal subject for this approach. Because of the prevalence of breast cancer, it is recommended that such a seminar become an integral part of the preclinical curriculum for all female medical students.

Preventive health care for older patients

This chapter addresses key components of screening and preventive care for the older population. The older population is heterogeneous, ranging from the competent, active, well individual to the frail, demented individual. Certain preventive measures are important for all individuals such as counseling on exercise and screening for high blood pressure. However, universal cancer, cholesterol, or dementia screening may not be cost effective and beneficial in all older adults. These preventive measures should be guided by the individuals' circumstances including their life expectancy, co-morbid illnesses, functional capacity, and quality of life. Clinicians may be able to individualize preventive medicine decisions by stratifying their patients into well and frail using the guidelines we have provided. The goal of prevention and screening in older patients is to improve function and quality of life. Primary care physicians should facilitate discussion of preventive measures with their older patients as part of their ongoing health care.

Cancer screening in the elderly population

This article reviews the current state of knowledge regarding cancer screening in the geriatric population. Care of the elderly requires knowledge of underlying physiologic changes, comorbidities, quality-of-life factors, and life expectancies. There is always the danger that ageism may prevent elderly cancer patients from receiving the proper treatment. On the other hand, overzealous treatment can lead to adverse results if elderly patients are not properly targeted based on current evidence of the benefits and risks of specific screening practices.

Breast cancer screening

PURPOSE AND DESIGN

Three breast cancer screening methods are commonly employed: mammography, breast self examination (BSE), and physical examination by trained personnel (PE). Case-control, retrospective, and prospective studies have examined the efficacy of these screening modalities in reducing breast cancer mortality. However, there are three biases pertinent to many of these studies: lead-time, length, and selection biases. The best way to exclude these biases is to compare screened and unscreened women in a randomized controlled trial with breast cancer mortality as the end point. Eight trials have examined the effect of mammographic screening on breast cancer mortality and two have examined the impact of screening with BSE. In addition, a large trial will soon be initiated in India to assess the impact of screening by PE on breast cancer mortality. This article reviews these trials and discusses the implications of the studies.

RESULTS

The overall results of the randomized controlled trials indicate that mammographic screening in women over age 50 can reduce breast cancer mortality by about 25%. However, its efficacy in women between the ages of 40 and 49 is disputed, and another large trial has been initiated in the United Kingdom to resolve this controversy. Preliminary results of two trials indicate that BSE has no impact on breast cancer mortality. However, longer follow-up of these trials is necessary before drawing any conclusions regarding BSE.

CONCLUSIONS

Mammographic screening in postmenopausal women is an effective means of reducing breast cancer mortality. However, the impact of mammographic screening on breast cancer mortality in premenopausal women is disputed. At least four potentially harmful consequences of mammographic screening merit consideration: lead time effect, radiation exposure, false-positives, and overdiagnosis. Thus, women between the ages of 40 and 49, in particular, should be informed of the potential for benefit and harm prior to mammographic screening.

Current issues in mammographic breast cancer screening

Mammographic screening for the early detection of breast cancer is widely accepted as the most effective means currently available to reduce breast cancer deaths. However, evidence shows that to maximize benefits and minimize harm, mammographic screening must be of high quality.

Future prospects for the staging of breast cancer

Rapidly growing knowledge about the nature and behaviour of breast cancer has led to many treatment modalities. Consequently, the possibilities of individualizing the treatment of breast cancer increase. The major tool for the determination of an optimal treatment plan is the estimation of the extent of the disease: in other words, staging. As a consequence, together with the expected result of the treatment, the stage of the disease gives information on the prognosis of the patient. Current staging systems insufficiently describe the clinically important features of breast cancer with respect to management and outcome: local and regional extent, invasiveness, aggressiveness, the state of dissemination, and the effectiveness of different treatment modalities. For staging of the local and regional extent, histology plays a prominent role and should be incorporated in future staging systems. Histological workup therefore needs standardisation. Histological parameters as tumour size, grade, nodal status, and vascular invasion are also the most important prognostic factors. Many so-called biological prognostic factors are related to the invasiveness and aggressiveness (metastatic potential) of the tumour, and therefore to the prognosis of the patient. However, these factors do not necessarily predict the effectiveness of certain systemic treatments. Only if the biological foundation of a prognostic factor is completely clarified can treatment be based on this knowledge, and the factor will become a predictor for the treatment effect. Many "biological" prognostic factors do not fulfil this main criterion and are therefore not useful for clinical decision making. A clinically useful staging system covers three primary aims: (1) to guide locoregional treatment, (2) to prognosticate the chance of survival, and (3) to indicate who needs what kind of adjuvant treatment. For the conception of a new staging system the following steps should be taken: standardization of all aspects of histology, identification of regional nodal involvement, and validation of prognostic factors with respect to their predictive value to treatment outcome.

Efficacy of breast cancer screening by age. New results from the Swedish Two-County Trial

BACKGROUND

Several studies have found a smaller effect of breast cancer screening on breast cancer mortality in women aged younger than 50 years compared with older women. Various possible reasons have been suggested for this, but none firmly is established.

METHODS

The Swedish Two-County Study is a randomized trial of breast cancer screening of women aged 40-74 years, comprising with 133,065 women with a 13-year follow-up of 2467 cancers. The Breast Cancer Detection Demonstration Project (BCDDP) is a nonrandomized screening program in the United States, with a 14-year follow-up of 3778 cancers in women aged 40-74 years. The Swedish results by age were updated. The lesser effect of screening at ages 40-49 years was investigated in terms of sojourn time (the duration of the preclinical but detectable phase) size, lymph node status, and histologic type of the tumors diagnosed in the Swedish Study and their subsequent effect on survival using survival data from both studies.

RESULTS

In the Swedish Trial, a 30% reduction in mortality associated with the invitation to screening of women aged 40-74 years was maintained after 13-years of follow-up. The reduction was 34% for women aged 50-74 years and 13% for women aged 40-49 years. Results indicated that the reduced effect on mortality for women aged 40-49 years was due to a differential effect of screening on the prognostic factors of tumor size, lymph node status, and histologic type. The mean sojourn times in the age groups 40-49 years, 50-59 years, 60-69 years, and 70-74 years were 1.7, 3.3, 3.8, and 2.6 years, respectively.

CONCLUSIONS

These results suggest that much, although not all, of the smaller effect of screening on mortality in women aged 40-49 years is due to faster progression of a substantial proportion of tumors in this age group and the rapid increase in incidence during this decade of life. It is concluded that the interval between screenings should be shortened to achieve a greater benefit in this age group. It is estimated that a 19% reduction in mortality would result from an annual screening regime.

Breast Cancer: A Revolutionary Concept

In this paper we trace the evolution of paradigms concerning the nature of breast cancer and their therapeutic consequences. There is no doubt that the conceptual revolution of about 20 years ago has led to modest gains in survival following the use of adjuvant systemic therapy and the quality of survival by demonstrating the safety of conservative surgical regimens. At the same time, there seems to be a plateau in progress. The results of adjuvant systemic therapy are not as good as anticipated and there are a number of other inconsistencies within the conventional model of biological predeterminism that remain to be explained. We offer up an alternative paradigm that suggests that not all metastases are due to cellular dissemination with late onset local and distant recurrence resulting from a transfection phenomenon, whereby subcellular particles shed by the primary cancer cell are taken up by wandering cells of the monocyte macrophage system and transported to distant sites where the local mesenchymal cells are transfected with the genetic information that activates components of the genome to instruct these plastic cells to express the phenotypic picture of a dedifferentiated breast duct epithelial cell. Such a conceptual revolution will open up the way for a new program of research and the development of therapies based on anti-viral rather than cytotoxic drugs.

Surgery for cure followed by chemotherapy in small cell carcinoma of the lung. For the ISC-Lung Cancer Study Group

The Lung Cancer Study Group of the International Society of Chemotherapy (ISC-LCSG) organized multinational, cooperative, prospective and randomized trials for the cure of patients with small cell lung cancer at early stages (T1,2N0M0). Surgery for cure was used first, followed by postoperative chemotherapy, and thereafter by prophylactic cranial irradiation. Eight cycles of standard chemotherapy (CAV-cyclophosphamide-doxorubicin-vincristine) or 6 intermittent cycles of alternating chemotherapy, using 3 different drug combinations, were administered 1-2 weeks postoperatively for 6 months after randomization. A total of 183 evaluable patients received surgery for cure at 23 cooperating hospitals. The preliminary evaluation of ISC-studies I and II per May 1993 resulted in the 30-month total survival of 63% from 68 patients after complete resection at TN0M0R0-stages and 37% from 27 patients after such resections at TN2M0R0-stages. Their incidence of local recurrence as first relapse was quite similar (11/47:8/39). The related 4-year recurrence-free survival (57%, 37%), indicating a plateau-like curve of long-term survivors. These promising results have to be confirmed by larger studies. We conclude that the indication for surgery as the first treatment step for SCLC should be the same as for the other non-small subtypes of lung cancers.

Computer model challenges breast cancer treatment strategy

The breast cancer treatment failure rate remains unacceptably high. The current breast cancer treatment paradigm, based primarily on Gompertzian kinetics and animal models, advocates short-course, intensive chemotherapy subsequent to tumor debulking, citing drug resistance and host toxicity as the primary reasons for treatment failure. To better understand treatment failure, we have studied breast cancer from the perspective of computer modeling. Our results demonstrate breast cancers grow in an irregular fashion; this differs from the Gompertzian mode of animal models and thus challenges the validity of the current paradigm. Clinical and laboratory data support the concept of irregular growth rather than the common claim that human tumors grow in a Gompertzian fashion. Treatment failure mechanisms for breast cancer appear to differ from those for animal models, and thus treatments optimize on animal models may not be optimal for breast cancer. A failure mechanism consistent with our results involves temporarily dormant tumor cells in anatomical or pharmacological sanctuary, which eventually result in aggressive metastatic disease.

Breast cancer 2000 BC to 2000 AD--time for a paradigm shift?

In this paper I trace the history of the development of the treatment of breast cancer over a 4000-year period. I point out that there have basically been three paradigms within which we have studied and developed treatment for this disease. Clinical trials over the last twenty years as an expression of the scientific method in action, have demonstrated the limited success of the contemporary paradigm with its therapeutic sequelae of breast conserving surgery and adjuvant systemic therapy. At the same time a critical review of the natural history of breast cancer and the results of current treatments suggest logical inconsistencies in the model. I have therefore constructed a novel paradigm which better fits the available information by suggesting that metastases are not only a result of cellular transmission of breast cancer but sub-cellular transmission using the mechanism of in vivo transfection. Although this may sound far fetched, there are a series of remarkable studies in the literature which supports this conceptual revolution. This is surely a fertile field for research and the therapeutic consequences would be obvious. They might suggest that more aggressive adjuvant systemic chemotherapy based on the conventional model is unlikely to achieve any additional benefit, whereas therapy based on anti-viral drugs might produce the next therapeutic advance. It is not the intention of this article to persuade readers that the alternative paradigm is true but merely to open minds to the study of history and scientific philosophy to ensure that we do not repeat the errors of the past.