Medical and legal implications of screening and follow-up procedures for breast cancer

Machine learning-based prediction of breast cancer growth rate in vivo

Background

Determining the rate of breast cancer (BC) growth in vivo, which can predict prognosis, has remained elusive despite its relevance for treatment, screening recommendations and medicolegal practice. We developed a model that predicts the rate of in vivo tumour growth using a unique study cohort of BC patients who had two serial mammograms wherein the tumour, visible in the diagnostic mammogram, was missed in the first screen.

Methods

A serial mammography-derived in vivo growth rate (SM-INVIGOR) index was developed using tumour volumes from two serial mammograms and time interval between measurements. We then developed a machine learning-based surrogate model called Surr-INVIGOR using routinely assessed biomarkers to predict in vivo rate of tumour growth and extend the utility of this approach to a larger patient population. Surr-INVIGOR was validated using an independent cohort.

Results

SM-INVIGOR stratified discovery cohort patients into fast-growing versus slow-growing tumour subgroups, wherein patients with fast-growing tumours experienced poorer BC-specific survival. Our clinically relevant Surr-INVIGOR stratified tumours in the discovery cohort and was concordant with SM-INVIGOR. In the validation cohort, Surr-INVIGOR uncovered significant survival differences between patients with fast-growing and slow-growing tumours.

Conclusion

Our Surr-INVIGOR model predicts in vivo BC growth rate during the pre-diagnostic stage and offers several useful applications.

Reduced mortality for women with mammography-detected breast cancer in east Denmark and south Sweden

The 5-year relative survival from breast cancer in Denmark is 10 percentage points lower than in Sweden. This difference has been demonstrated previously as being caused partly by more involved lymph nodes and larger tumours in Denmark. Sweden has had nationwide mammography-screening coverage since 1991, whereas this is still in its infancy in Denmark. In the search for an explanation for the remaining survival difference, patient delay was a likely candidate. This study compared patient delay and mammography-detection between two national regions. Data on patient delay and mammography were obtained from hospital records from 1989 and 1994, and analysed using Cox proportional hazard analysis of death within the first 5 years, with the factors age, country, delay/mammography detection and established patho-anatomic variables. A comparison of patient delay and mammography detection in 1989 and 1994 showed more mammography-detected tumours in south Sweden and more women with long delay in east Denmark. Mammography detection, but not long patient delay, had a significant effect on the death hazard when adjusting for patho-anatomic risk factors. The hazard ratio was not eliminated in 1989, but in 1994, the hazard ratio between east Denmark and south Sweden was reduced from 1.3 to 1.1. In conclusion, patient delay did not appear to have any effect on 5-year survival when adjusting for patho-anatomic factors, but tumour detection by mammography affected survival favourably and partly explained the survival difference between east Denmark and south Sweden.

Who's liable for breast cancer prevention? Your patient can sue--and win--if preventive options aren't made clear

Strategies to reduce the likelihood of breast cancer in high-risk patients present complex medical-legal issues. An accurate and thorough medical history, objective calculation of risk, thorough discussion of preventive options and side effects, meticulous documentation of physician-patient interactions, and meticulous follow-up are essential. These elements form the foundation of a sound approach to breast cancer prevention in high-risk patients and should reduce physician liability if cancer occurs.

Reassessment of breast cancers missed during routine screening mammography: a community-based study

OBJECTIVE

The purpose of this study was to have a series of screening mammograms from routine practice, including false-negative results, reviewed by peer community-based experienced radiologists to determine the percentage of these false-negative findings that might be considered detectable.

MATERIALS AND METHODS

All screening cases for 1997 and 1998 were identified from the Carolina Mammography Registry. Mammographic assessments from community mammography practices were linked with population-based cancer outcomes. The findings of four community-based radiologists who reviewed the mammograms of 339 asymptomatic women were 93 false-negatives, 180 true-negatives, and 66 false-positives. The percentage of false-negative, true-negative and false-positive findings on breast films that reviewers evaluated was determined. The findings of the reviewers were compared with the original interpreting radiologists' assessments.

RESULTS

The overall breast-specific workup rate by the reviewing radiologists was 21%. The average workup rate for the false-negative findings was 42% (range, 35-51%). Adjusting for the 13% workup rate in the cancer-free breasts, the percentage of false-negative findings that were detectable was estimated to be 29%.

CONCLUSION

This peer review of screening mammograms from a population-based screening registry estimated a missed detectable cancer rate of 29%. Thus, 71% of cancers missed at screening would not have been worked up by peers in the same community.

Delay in the diagnosis of breast cancer: medico-legal implications

Delay in the diagnosis of breast cancer is an important cause of medical malpractice claims which if trends continue, will threaten healthcare budgets. Most malpractice claims are made by younger women. Delay is most frequently due to the physician failing to be impressed with the clinical findings, or to a false negative mammogram report. Diagnosis of breast cancer is more difficult in younger women, because of the poor sensitivity of diagnostic tests and the high prevalence of benign disease in this age group. Models of tumour growth suggest that the potential to metastasize may be present before the tumour is clinically detectable and that if the growth rate of a given tumour is constant, any clinical delay is a small proportion of the lifespan of the tumour. Patient delay is generally associated with more advanced lesions at presentation, but the effect of delay on survival or what period of delay is significant remains uncertain. Delay in the diagnosis of breast cancer is likely to cause the patient considerable anxiety, especially when the public understands that the aim of mammographic screening is to diagnose breast cancer at an early stage in order to effect a cure. For a plaintiff to successfully claim in court she must prove that she has suffered an injury, and that the injury was the result of negligent medical practice. It is easier to defend a case of delay in diagnosis if the documentation is in order and all the appropriate tests have been performed.

Differences in the quality of care for women with an abnormal mammogram or breast complaint

OBJECTIVE

To examine factors associated with variation in the quality of care for women with 2 common breast problems: an abnormal mammogram or a clinical breast complaint.

DESIGN

Cross-sectional patient survey and medical record review.

SETTING

Ten general internal medicine practices in the Greater Boston area.

PARTICIPANTS

Women who had an abnormal radiographic result from a screening mammogram or underwent mammography for a clinical breast complaint (N = 579).

MEASUREMENTS AND MAIN RESULTS

Three measures of the quality of care were used: (1) whether or not a woman received an evaluation in compliance with a clinical guideline; (2) the number of days until the appropriate resolution of this episode of breast care if any; and (3) a woman's overall satisfaction with her care. Sixty-nine percent of women received care consistent with the guideline. After adjustment, women over 50 years (odds ratio [OR], 1.58; 95% [CI], 1.06 to 2.36) and those with an abnormal mammogram (compared with a clinical breast complaint: OR, 1.75; 95% CI, 1.16 to 2.64) were more likely to receive recommended care and had a shorter time to resolution of their breast problem. Women with a managed care plan were also more likely to receive care in compliance with the guideline (OR, 1.72; 95% CI, 1.12 to 2.64) and have a more timely resolution. There were no differences in satisfaction by age or type of breast problem, but women with a managed care plan were less likely to rate their care as excellent (43% vs 53%, P <.05).

CONCLUSIONS

We found that a substantial proportion of women with a breast problem managed by generalists did not receive care consistent with a clinical guideline, particularly younger women with a clinical breast complaint and a normal or benign-appearing mammogram.

Breast masses in African American teenage girls

PURPOSE

The aim of this study was to evaluate the incidence of malignancy in breast lumps excised from African American teenagers.

METHODS

The authors reviewed the pathology records at King's County Hospital Center between January 1982 and December 1992. The pathology reports and charts of all patients who had breast masses excised during this period were reviewed. Data for this study were derived from the group of African American and black Caribbean American teenage patients who underwent breast biopsies and whose pathology reports and medical records were available. The age of patients, size of the lesion, and diagnosis were recorded.

RESULTS

Medical records from 155 African American and black Caribbean American girls between the ages of 13 and 19 years (inclusive) who underwent breast biopsies between January 1982 and December 1992 were reviewed. Fibroadenoma was the most common diagnosis (127 of 155; 82%). This was followed in frequency by fibrocystic mastopathy (18 of 155; 11.6%) and breast abscess (3 of 155; 2%). None of the patients had a malignancy. Review of tumor registry data from the same time period at Kings County Hospital Center and the University Hospital of Brooklyn showed that the youngest African American or black Caribbean American patient diagnosed with breast cancer was 21 years of age.

CONCLUSIONS

The incidence of malignant breast lumps in African American and black Caribbean American teenagers is distinctly low. Conservative treatment in this population is warranted, and diagnosis can be made easily in most cases with either needle aspiration for cytology or core biopsy of any lesions discovered.

Physician characteristics: do they influence the evaluation and treatment of breast cancer in older women?

BACKGROUND

To determine if physician specialty, length of time in practice, and fear of malpractice influence the diagnosis and management of breast cancer in older women.

METHODS

We used a fractional factorial design that controlled for patient age (65 or 80 years), race, socioeconomic status, mobility, comorbidity, and assertive behavior through 2 videotaped scenarios (a potential breast cancer [no. 1] and a known stage IIA breast cancer [no. 2]). One hundred twenty-eight white male physicians equally divided by specialty (surgeon versus nonsurgeon) and time in practice (< or = 15 or >15 years) viewed the videotapes and made recommendations.

RESULTS

The physician subjects saw 46 patients per week, 59% female, and 47% age > or = 65. Their concern over malpractice was 4.7 (on a 10-point Likert scale with a higher score indicating more concern) and did not differ by specialty or time in practice (P values > 0.7). After viewing scenario no. 1, surgeons were less likely than nonsurgeons to consider breast cancer as the principal diagnosis (odds ratio [OR] = 0.4, 95% confidence interval [CI] = 0.2 to 0.9) and to obtain a tissue diagnosis (OR = 0.3, 95% CI = 0.1 to 0.9). However, in scenario no. 2, surgeons were more likely to offer reconstruction (OR = 3.8, 95% CI = 1.4 to 10.4). Physicians in practice < or = 15 years were more likely than those in practice <15 years to obtain a tissue diagnosis in scenario no. 1 (OR = 6.1, 95% CI = 1.9 to 19.2) and to perform full primary therapy in scenario no. 2 (OR = 2.8, 95% CI = 1.2 to 6.9). Physicians who performed an extensive metastatic evaluation (bone or computer tomography [CT] scan) had greater concern over malpractice than those who did not, as did physicians who performed an axillary node dissection (OR = 2.1, 95% CI 1.3 to 3.4 and OR = 1.8, 95% CI = 1.1 to 3.0).

CONCLUSIONS

With the uncertainty of how to diagnose and treat older women with breast cancer, physician specialty, length of time in practice, and concern over malpractice do influence clinical decisions.

On the growth rates of human malignant tumors: implications for medical decision making

Testicular carcinomas, pediatric tumors, and some mesenchymal tumors are examples of rapidly proliferating cell populations, for which the tumor volume doubling time (TVDT) can be counted in days. Cancers from the breast, prostate, and colon are frequently slow-growing, displaying a TVDT of months or years. Irrespective of their growth rates, most human tumors have been found: to start from one single cell, to have a long subclinical period, to grow at constant rates for long periods of time, to start to metastasize often even before the primary is detected, and to have metastases that often grow at approximately the same rate as the primary tumor. The recognition of basic facts in tumor cell kinetics is essential in the evaluation of important present-day strategies in oncology. Among the facts emphasized in this review are: (1) Screening programs. Most tumors are several years old when detectable by present-day diagnostic methods. This makes the term "early detection" questionable. (2) Legal trials. The importance of so-called doctor's delay is often discussed, but the prognostic value of "early" detection is overestimated. (3) Analyses of clinical trials. Such analysis may be differentiated depending on the growth rates of the type of tumor studied. Furthermore, uncritical analysis of survival data may be misleading if the TVDT is not taken into consideration. (4) Analyses of epidemiological data. If causes of malignant tumors in humans are searched for, the time of exposure must be extended far back in the subject's history. (5) Risk estimations by insurance companies. For the majority of human cancers, the 5-year survival rate is not a valid measurement for cure. Thus, basic knowledge of tumor kinetics may have important implications for political health programs, legal trials, medical science, and insurance policies.

Patient, physician and presentational influences on clinical decision making for breast cancer: results from a factorial experiment

This study examines the influence of six patient characteristics (age, race, socioeconomic status, comorbidities, mobility and presentational style) and two physician characteristics (medical specialty and years of clinical experience) on physicians' clinical decision making behaviour in the evaluation treatment of an unknown and known breast cancer. Physicians' variability and certainty associated with diagnostic and treatment behaviour were also examined. Separate analyses explored the influence of these non-medical factors on physicians' cognitive processes. Using a fractional factorial design, 128 practising physicians were shown two videotaped scenarios and asked about possible diagnoses and medical recommendations. Results showed that physicians displayed considerable variability in response to several patient-based factors. Physician characteristics also emerged as important predictors of clinical behaviour, thus confirming the complexity of the medical decision-making process.

The timely diagnosis of breast cancer. Principles of risk management for primary care providers and surgeons

Alleged delay in the diagnosis of breast cancer is one of the most common reasons for medical malpractice claims in the United States, accounting for the largest indemnity payments of any single medical condition. Although the diagnosis of breast cancer can be challenging and sometimes difficult, principles of management exist to assist health providers in pursuing a resolution of any breast complaint. Studies have shown that when litigation is pursued for alleged failure to diagnose breast cancer, multiple specialists are named in the suit. In most cases, patients filing claims of alleged failure to diagnose breast cancer are premenopausal, while the majority of women diagnosed with breast cancer are postmenopausal. This reflects, in part, the challenge of diagnosing the disease in women who have difficult clinical exams to interpret, as well as dense parenchyma on mammograms, which decreases the sensitivity of the radiograph interpretation. Principles of risk management to avoid a delay in diagnosis include (1) pursuing every breast complaint to resolution, (2) following breast cancer screening guidelines, (3) establishing an office tracking system for breast cancer screening reminders, (4) tracking results of all mammograms and follow-up studies ordered, (5) referring premenopausal women for the evaluation of any breast mass that persists through a menstrual cycle, (6) considering any asymmetrical breast finding as a cause for concern, (7) referring every woman with a breast finding on physical examination for consultation, regardless of the mammogram report, and (8) carefully documenting patient history, physical exam findings, clinical impression, and follow-up plans.

Breast biopsy in women 30 years old or less

Forty women 30 years of age or less underwent breast biopsy at Roswell Park Cancer Institute between January 1980 and January 1989. Thirty-eight of the 40 women had a palpable breast mass. Thirty-one of these young women had self-detected breast masses, and the median duration before presentation was 6 months. Physical characteristics were described in 30 of the masses. Twenty-three were described as "fibroadenomas" or smooth, firm, and mobile. Seven masses were described as irregular. The median size of the breast mass was 1.5 cm (range: 0.5 to 9.0 cm). Mammography was performed in 20 patients, but results were reported as abnormal in only 6. Twenty of the masses were described histologically as fibroadenoma. Twelve were described histologically as "fibrocystic disease" or "stromal fibrosis." One case (2.5%) was invasive adenocarcinoma. Probability of serious underlying breast pathology in young women is low but not nil. Noninvasive and minimally invasive techniques are proposed by some authors as cost-efficient methods that may substitute for open biopsy in these patients. Unfortunately, false-negative results persist and are particularly unacceptable in these young women. During the same time period as our study, 54 women aged 30 years or less were referred to Roswell Park Cancer Institute with a previously diagnosed invasive breast cancer. The incidence of breast cancer in this biopsy series was 2.5%. The potential costs of misdiagnosed early breast cancer in young women negate any rationalization for less invasive biopsy techniques. Following aspiration to rule out a benign cyst, and a possible period of brief observation for spontaneous resolution (2 or 3 months), excisional biopsy is recommended for young women with a breast mass.

Routine follow-up of patients after primary therapy for early breast cancer: changing concepts and challenges for the future

In an era of increasing financial constraints, physicians are being forced to critically re-evaluate various clinical practices that have not been shown to be cost-effective or associated with definitive patient benefit. Routine follow-up programs following primary therapy for early-stage breast cancer vary widely from centre to centre, and although the subject of numerous retrospective analyses, they have not been prospectively evaluated to date. This review paper presents arguments for changing the emphasis of follow-up visits and stresses the need for prospective clinical and cost-benefit evaluations of current follow-up practices.

The anatomy of missed breast cancers

Missed breast cancer continues to account for the highest percentage of medical malpractice cases in the United States. A retrospective, computer-aided study was performed to investigate the mechanisms of missed breast carcinomas, missed either by mammography or by clinical exam. In a consecutive series of 509 breast cancers found in patients registered at a University Comprehensive Breast Cancer Clinic, no tumour that was 5 mm or less in maximal diameter was clinically palpable. This subgroup consisted of seven in situ and 32 invasive carcinomas. The incidence of palpable tumours in 5 mm increments increased so that when a tumour was between 11 and 15 mm in size, 48% of the lesions were palpable, and with tumours greater than 20 mm in size, 84% were palpable. There was a good correlation between size of the tumour as judged by mammography and the eventual size determined by histologic examination. Smaller breast cancers were detected by mammography than by physical examination. In a separate analysis of 553 consecutive cases of breast cancer examined by mammography, there were 50 (9%) cases in which the cancer was not read from the mammogram. In retrospect, 10 of these mammograms were abnormal for a misinterpretation rate of 1.8%. Cancers associated with false negative mammograms occurred more often in younger women and in dense breast parenchyma than cancers detected by mammography. Cancers missed by mammography were smaller than palpable cancers detected by mammography, more often had negative nodes and presented with a lower stage of disease. Breast augmentation implants were associated more frequently with missed breast cancers, with 5/8 clinically detected breast carcinomas being undetected by mammography. An asymmetric mass was more often associated with cancers missed by mammography, accounting for the sole sign of malignancy in 3% of all cancers, but was the source of 14% of false negative exams. Architectural distortion, ill-defined or well circumscribed masses or calcifications as mammographic signs of malignancy were not associated with an increased frequency of missed cancers. Three 'interval' breast cancers occurred in this series and are included in the false negative mammograms. It is concluded that the threshold of clinically detected breast cancers is 6 mm and experienced clinicians do not detect the majority of breast cancers until the lesions are greater than 16 mm. Mammography has a defined misinterpretation and false negative rate. Likewise, asymmetric mammographic densities that are greater than 16 mm and are not palpable may be followed, since most breast cancers are palpable in this range.

Comparisons of strategies to prevent breast cancer mortality

A health system should meet the health needs of the population. Given limited resources, choices are made about problems--typically, diseases--to attack. Then, choices must be made as to how to identify, treat, and ultimately, prevent their occurrences. This process is the subject of this article; it uses the case of breast cancer to examine allocation of resources to disease prevention and treatment. The paper reviews current allocation patterns among three strategies for prevention: primary, secondary, and tertiary. Each varies with respect to where the disease process is halted and in the amount of technological support required. Currently, the U.S. health care system allocates most resources to tertiary prevention, with scant support of primary and limited support of secondary prevention. Possible explanations for the current allocation patterns are discussed. Areas where social sciences have made contributions are highlighted. Finally, cost-effectiveness analyses are presented to illustrate a relatively balanced method for making decisions about future allocations.

Legal issues in managing breast disease

The impact of legal issues in breast cancer care reflects the significance of breast cancer as a health concern of women. Breast cancer has emerged as a leading liability risk for primary care physicians, with most cases focusing on delayed diagnosis. Although the clinical impact of delayed diagnosis of breast cancer is often controversial, physicians should strive to diagnose breast cancer as early as possible in the natural history of the disease. No currently available data suggest that a delay of less than 2 months between the onset of symptoms and diagnosis or treatment adversely influences outcome. Techniques that help physicians reduce the liability risks associated with breast cancer care include patient education, adequate documentation and follow-up, and referral or consultation in high-risk situations.

[The effectiveness of breast cancer screening in our country]

The aim of this paper is to review the current state of breast cancer screening in our country, as well as to discuss the most appropriate approaches for its development. Firstly, the impact of breast cancer in Spain is presented, as well as the current evidence about the efficacy of the screening. The major programs and initiatives addressed to promote screening are described. Finally, a few recommendations are given in order to achieve that breast cancer screening be, not only efficacious, but also effective. It is concluded that it is necessary that health and professional authorities coordinate and monitor breast cancer screening programs.

Audit of mammography in a community setting

A Northwest community concentrated all mammography services in one location and instituted a program of annual review. The 32,118 mammograms prompted 466 biopsies of women who had no palpable abnormality. Over the 5-year study, there were 142 nonpalpable cancers found for a positive biopsy rate of 30%. In the first year, the positive biopsy rate was 17%, and, in the last year, it was 42%. The increase in apparent selectivity prompted a search for false negatives or missed breast cancers. One percent of women subjected to mammography underwent biopsy, but, interestingly, only 84% of women undergoing mammography received a normal report. Eighty-seven percent of the cancers were invasive, and 13% were considered to be noninvasive. A review of the literature suggests significant variation in the frequency of identifying nonpalpable breast cancer, and respected pathologists report variations in the pathologic evaluation of these nonpalpable cancers.