Does the intent to irradiate the internal mammary nodes impact survival in women with breast cancer? A population-based analysis in British Columbia

PURPOSE

To determine the value of the intent to include internal mammary nodes (IMNs) in the radiation therapy (RT) volume for patients receiving adjuvant locoregional (breast or chest wall plus axillary and supraclavicular fossa) RT for breast cancer.

METHODS AND MATERIALS

2413 women with node-positive or T3/4N0 invasive breast cancer, treated with locoregional RT from 2001 to 2006, were identified in a prospectively maintained, population-based database. Intent to include IMNs in RT volume was determined through review of patient charts and RT plans. Distant relapse free survival (D-RFS), breast cancer-specific survival (BCSS), and overall survival (OS) were compared between the two groups. Prespecified pN1 subgroup analyses were performed.

RESULTS

The median follow-up time was 6.2 years. Forty-one percent of study participants received IMN RT. The 5-year D-RFS for IMN inclusion and exclusion groups were 82% vs. 82% (p = 0.82), BCSS was 87% vs. 87% (p = 0.81), and OS was 85% vs. 83% (p = 0.06). In the pN1 subgroup, D-RFS was 90% vs. 88% (p = 0.31), BCSS was 94% vs. 92% (p = 0.18), and OS was 91% vs. 88% (p = 0.01). After potential confounding variables were controlled for, women who received IMN RT did not have significantly different D-RFS (hazard ratio [HR] = 1.02 (95% confidence interval [CI], 0.84-1.24; p = 0.85), BCSS (HR = 0.98 (95% CI, 0.79-1.22; p = 0.88), or OS (HR = 0.95; 95% CI, 0.78-1.15; p = 0.57). In the pN1 subgroup, IMN RT was associated with trends for improved survival that were not statistically significant: D-RFS (HR = 0.87; 95% CI, 0.63-1.22; p = 0.42), BCSS (HR = 0.85; 95% CI, 0.57-1.25; p = 0.39), and OS (HR = 0.78; 95% CI, 0.56-1.09; p = 0.14).

CONCLUSIONS

After a median follow-up time of 6.2 years, although intentional IMN RT was not associated with a significant improvement in survival, this population-based study suggests that IMN RT may contribute to improved outcomes in selected patients with N1 disease.

Promoting consultation recording practice in oncology: Identification of critical implementation factors and determination of patient benefit

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Background: The objectives of this implementation study were to 1) identify and address the evidentiary, contextual, and facilitative mechanisms that serve to retard or promote the transfer and uptake of consultation recording use in oncology practice, and 2) follow patients during the first few days following receipt of the consultation recording to document, from the patient’s perspective, the benefits realized from listening to the recording.

Methods: Nine medical and 9 radiation oncologists from cancer centers in three Canadian cities (Calgary, Vancouver, Winnipeg) recorded their primary treatment consultations for 228 patients newly diagnosed with prostate or breast cancer. The Digital Recording Use Semi-Structured Interview (DRUSSI) was conducted at two days post-consultation and at 1-week post-consultation. Each oncologist was given a feedback letter summarizing the consultation recording benefits reported by their patients.

Results: Sixty-nine percent of patients listened to at least a portion of the recording within the first week following the consultation. Consultation recording favourableness ratings were high: 93.6% rated the intervention between 75–100 on a 100-point scale. Four main areas of benefit were reported: 1) Anxiety reduction; 2) Enhanced retention of information; 3) Better informed decision making; and 4) Improved communication with family members. Eight fundamental components of successful transfer and uptake of consultation recording practice were identified.

Conclusions: Implementation research and additional randomized trials are needed to facilitate the transfer and uptake of consultation recording use so that far more patients and significant others may realize the associated benefits.

Age over 80 years is not associated with increased hemorrhagic transformation after stroke thrombolysis

Thrombolysis trials have recruited few patients aged ≥80 years, which has led to uncertainty about the likely risk-to-benefit profile in the elderly. Leukoaraiosis (LA) has been associated with hemorrhagic transformation (HT) and increases with advanced age. We tested whether there were any independent associations between age, LA and HT. Consecutive patients treated with intravenous (IV) tissue plasminogen activator (tPA) were identified from a prospective database. LA on baseline CT scans was assessed by two independent raters using the modified Van Swieten Score (mVSS) (maximum score 8, severe >4). HT was assessed on routine 24 hour to 48 hour CT /MRI scans using the European Cooperative Acute Stroke Study criteria for hemorrhagic infarct (HI) or parenchymal hematoma (PH) and judged symptomatic by the treating neurologist as per Safe Implementation of Thrombolysis in Stroke criteria. There were 206 patients treated with IV tPA (mean age: 71.0 years; range: 24-92 years), of whom 65/206 (32%) were aged ≥80 years. Overall, HT occurred in 41/206 patients (20%), HI in 31, PH1 in four (one symptomatic) and PH2 in six (three symptomatic). Age was not associated with HT (any HT: odds ratio [OR]=1.01; 95% confidence interval [CI]=0.5-2.08; p=0.99; PH: OR=0.53; 95% CI=0.12-2.3; p=0.51). There was one patient with PH1 and one patient with PH2 in 65 patients ≥80 years, both asymptomatic. LA was present in 112/208 (54%), and severe in 16.5%. LA increased with age (p<0.001) but was not associated with PH (any LA: OR=0.83; 95% CI=0.25-2.8; p=0.99; severe LA: OR=0.54, 95% CI=0.09-3.5; p=0.99). Age ≥80 years or LA did not increase the risk of HT (including PH) after thrombolysis, although LA increased with age. Neither factor should exclude otherwise eligible patients from tPA treatment.

Impact of internal mammary node inclusion in the radiation treatment volume on the outcomes of patients with breast cancer treated with locoregional radiation after six years of follow-up

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Background: There is ongoing controversy about radiotherapy (RT) to internal mammary nodes (IMNs). Proponents of IMN RT cite the survival benefit seen in postmastectomy RT trials that included IMNs. However, others point out that benefit cannot be definitively attributed to IMN inclusion, as other lymph node regions were included in the RT arms. The issue is important, as IMN RT potentially increases cardiac and respiratory morbidity.

Methods: 2,413 women referred to a provincial RT program with newly diagnosed node positive, or T3/4N0 non-M1 invasive breast cancer, treated with a complete course of locoregional RT from 2001 to 2006, were retrospectively identified in a provincial database. IMN RT inclusion versus exclusion was determined through review of patient charts and RT treatment plans. Breast cancer-specific survival (BCSS), relapse-free survival (RFS), and overall survival (OS) were compared between the two groups using univariate and multivariable analyses.

Results: Analyses were performed at a median follow-up of 6.2 years. 41.4% of the subjects received IMN RT. The 5-year BCSS for the IMN inclusion and exclusion group was 84.8% versus 82.9%, respectively (HR 0.93 [95% CI 0.76, 1.14]; p=.51); the 5-year RFS was 87.4% versus 86.9% (HR 0.993 [0.83, 1.19]; p=0.94); and the 5-year OS was 84.8% versus 82.9% (HR 0.84 [0.70, 1.01]; p=0.06). After controlling for potentially confounding variables, there was no significant difference in BCSS (HR 0.96 [0.78, 1.18], p=0.88), RFS (HR 1.02 [0.84, 1.22], p=0.87), or OS (HR 0.91 [0.76, 1.10]; p=0.35).

Conclusions: After a median follow-up of 6.2 years, this population-based study shows no benefit from including IMNs in the locoregional RT volume after adjusting for other prognostic and treatment variables.

Abstract P4-11-03: The Impact of Fractionation on Local Relapse for Patients with Grade 3 Breast Cancer

Background: Several randomized trials have demonstrated that hypofractionated (HF) and conventionally fractionated (CF) radiotherapy (RT) provide equivalent local control following breast conserving surgery (BCS). However, an update of the Canadian trial suggested that patients with grade 3 disease had an increased risk of local relapse after HF. The risk of local relapse following HF or CF according to grade was investigated among a population-based cohort from British Columbia, Canada. Materials and methods: Female patients diagnosed between 1990 and 2000 with T1-T2N0M0 breast cancer treated with lumpectomy, axillary dissection and RT with at least 6 nodes removed and RT delivered to the breast were identified. Whole breast RT prescriptions were distributed in two groups : HF (typically 42.5 to 44 Gy in 16 fractions), and CF (45Gy to 50 Gy in 25 fractions). The 45 Gy prescription was followed by a boost to the biopsy cavity regardless of the margin status. Patients with close or positive margins received a boost (typically 7.5 to 10Gy in 3 to 4 fractions, or 10 to 20Gy in 5 to 10 fractions). Baseline demographic (age, year of diagnosis), tumour (grade, histology, size, lymphatic vascular space invasion (LVI), presence of extensive DCIS) and treatment factors (margin status, hormonal or chemotherapy use, RT fractionation group, and RT boost use) were abstracted. Cumulative rates of local relapse were estimated using a competing risk approach (distant relapses or death were competing risks) and compared across groups using Gray's test. Factors significant on univariate analysis were included with fractionation group in a multivariate (Fine and Gray) model among grade 3 patients. Results: The cohort consisted of 1,335 patients diagnosed with grade 3 breast cancers: 252 received CF and 1083 patients received HF. The fractionation groups were well balanced for most of the aforementioned factors except median age (56 years for CF vs 52 years for HF (P&lt;0.01), and use of systemic therapy (hormones alone: 26% vs 19%; chemotherapy alone: 27%vs 33%; and chemo+hormone therapy: 8% vs 10% (p=0.04) for HF compared to CF). The 10-year cumulative incidence rate of local relapse in patients with grade 3 breast cancers was 6.9% for the HF group and 6.2 % for the CF group (p=0.99). A Fine and Gray multivariate competing risk model showed that age under 40 years (p=0.02), positive margins (p=0.05) and negative ER status (p=0.01) were associated with an increased risk of local relapse, but fractionation group was not (Hazard ratio=0.95, p=0.88).

Conclusions: There was no evidence that hypofractionation was inferior to conventional fractionation for breast conserving therapy in patients with T1-T2 N0, grade 3 breast cancer in a population-based series.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-03.

Predictors of distress and quality of life in patients undergoing cancer therapy: impact of treatment type and decisional role

PURPOSE

The purpose of this secondary investigation was to examine the impact of the type of treatment received and the perceived role in treatment decision making in predicting distress and cancer-specific quality of life in patients newly diagnosed with breast or prostate cancer.

METHOD

Participants included 1057 newly diagnosed breast and prostate cancer patients from four Canadian cancer centers who partook in a randomized controlled trial examining the utility of providing patients with an audio-recording of their treatment planning consultation. A MANCOVA was performed to predict distress and cancer-specific quality of life at 12 weeks post-consultation based on control variables (patient age, education, residence, tumor size (breast sample), gleason score (prostate sample), and receipt of an initial treatment consultation recording), predictor variables (treatment type--chemotherapy, hormone therapy, radiation therapy; decisional role--active, collaborative, passive), and interactions between these predictors.

RESULTS

Women who received chemotherapy and reported having played a more passive role in treatment decision making had significantly greater distress and lower cancer-specific quality of life at 12-week post-consultation. There were no statistically significant predictors of these outcomes identified for men with prostate cancer.

CONCLUSION

Receipt of chemotherapy places women with breast cancer at risk for distress and reduced quality of life, but only for the subset of women who report playing a passive role in treatment decision making. Prospective, longitudinal studies are needed to confirm the present findings and to explicate the antecedents, composition, and consequences of the 'passive' decisional role during the treatment phase of the cancer trajectory.

Behind closed doors: systematic analysis of breast cancer consultation communication and predictors of satisfaction with communication

OBJECTIVE

The purpose of this investigation was to explicate the content of primary adjuvant treatment consultations in breast oncology and examine the predictive relationships between patient and oncologist consultation factors and patient satisfaction with communication.

METHODS

The recorded consultations of 172 newly diagnosed breast cancer patients from four Canadian cancer centers were randomly drawn from a larger subset of 481 recordings and examined by three coders using the Medical Interaction Process System (MIPS); a system that categorizes the content and mode of each distinct utterance. The MIPS findings, independent observer ratings of patient and oncologist affective behavior, and derived consultation ratios of patient centeredness, patient directedness, and psychosocial focus, were used to predict patient satisfaction with communication post-consultation and at 12-weeks post-consultation.

RESULTS

Biomedical content categories were predominant in the consultations, accounting for 88% of all utterances, followed by administrative (6%) and psychosocial (6%) utterances. Post-consultation satisfaction with communication was significantly higher for older patients, those with smaller primary tumors and those with longer consultations. Smaller tumor, lack of patient assertiveness during the treatment consultation and having the consultation with a radiation rather than medical oncologist were significantly predictive of greater satisfaction at 12-weeks post-consultation.

CONCLUSIONS

Adjuvant treatment consultations are characterized by a high degree of information-giving by the physician, a predominance of biomedical discussion and relatively minimal time addressing patients' psychosocial concerns. Controlled trials are needed to further identify and address the contextual features of these consultations that enhance patient satisfaction.

Professionalization as a governance strategy for synthetic biology

This article considers professionalization as a governance strategy for synthetic biology, reporting on social science interviews done with scientists, science journal editors, members of science advisory boards and authors of nongovernmental policy reports on synthetic biology. After summarizing their observations about the potential advantages and disadvantages of the professionalization of synthetic biology, we analyze professionalization as a strategy that overcomes dichotomies found in the current debates about synthetic biology governance, specifically "top down" versus "bottom up" governance and scientific fact versus public values. Professionalization combines community and state, fact and value. Like all governance options, professionalization has limitations, particularly regarding war and peace. It is best conceptualized as potentially part of a wider range of governance mechanisms working in concert: a "web of prevention".

The Concept of Truth Regime

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Psychosocial barriers to active surveillance for the management of early prostate cancer and a strategy for increased acceptance

OBJECTIVES

To review the psychosocial needs of men undergoing active surveillance (AS, the monitoring of early prostate cancer, with curative intervention only if the disease significantly progresses) for prostate cancer, and barriers to its uptake.

METHODS

The introduction of screening for prostate-specific antigen (PSA) has led to more men diagnosed with early and nonlife-threatening forms of prostate cancer; about half of men diagnosed as a result of PSA testing have cancers that would never cause symptoms if left untreated and yet up to 90% of such men receive curative therapy, then living with the toxicity of treatment but with no benefit. Thus AS is increasingly being promoted, but if such a strategy is to succeed, the psychosocial barriers that discourage men from adopting AS must be addressed. We reviewed and assessed reports on this topic, published in English since 1994.

RESULTS

There is relatively little research on AS, as most published reports refer to watchful waiting (which is a palliative management approach). Men with prostate cancer generally have lower levels of psychological disturbance than for other cancers, but the psychosocial issues identified include anxiety in response to no intervention, uncertainty related to loss of control, and lack of patient education and support, particularly around the time of initial treatment planning. Approaches that were identified to improve uptake of AS include increased education and improved communication, interventions to reduce anxiety and uncertainty, and the empowerment of patients by the development of a sense of control and meaning. Physicians attitudes are influential and the education of physicians about AS as an appropriate option is to be encouraged. Peer-support groups were also identified as being of particular value.

CONCLUSIONS

There are several strategies that should be developed if AS is to become more widely adopted. Increased education and good communication can alleviate anxiety and uncertainty, as can interventions for cognitive re-framing. Inviting patients to become active participants in their management might enhance the patients' sense of control, and the involvement of peer-support groups might be beneficial.

Standardized audiotape versus recorded consultation to enhance informed consent to a clinical trial in breast oncology

BACKGROUND

The purpose of this study was to systematically compare two audiotape formats for the delivery of information relevant to informed consent to participate in a clinical trial in breast oncology, and to establish the feasibility of adding a consultation recording protocol to a clinical treatment trial.

METHOD

Participants were 69 women with newly diagnosed breast cancer and 21 oncologists from 5 Canadian cancer centers. Patients were block randomized to one of three groups: 1. standardized audiotape; 2. consultation audiotape; or 3. both audiotapes. Patients received their tapes immediately following the clinical trial consultation. Patient outcomes included perception of being informed about clinical trials, knowledge of information relevant to providing informed consent to a clinical trial, and satisfaction with communication during the consultation.

RESULTS

The consultation audiotapes contained less trial-related information than the standardized audiotape but there were no differences in clinical trial knowledge or perception of being informed across the intervention groups. Patients expressed a marginally significant preference for consultation audiotapes over standardized audiotapes.

CONCLUSIONS

Patients tended to prefer receiving an audiotape of their own consultation over a standardized audiotape. The majority of oncologists considered the audiotape intervention feasible but were less enthusiastic about being involved in a larger study given the accrual challenges that arose when trying to "piggy-back" one randomized controlled trial on an existing clinical trial.

Consistency in seroma contouring for partial breast radiotherapy: Impact of guidelines

PURPOSE

Inconsistencies in contouring target structures can undermine the precision of conformal radiation therapy (RT) planning and compromise the validity of clinical trial results. This study evaluated the impact of guidelines on consistency in target volume contouring for partial breast RT planning.

METHODS AND MATERIALS

Guidelines for target volume definition for partial breast radiation therapy (PBRT) planning were developed by members of the steering committee for a pilot trial of PBRT using conformal external beam planning. In phase 1, delineation of the breast seroma in 5 early-stage breast cancer patients was independently performed by a "trained" cohort of four radiation oncologists who were provided with these guidelines and an "untrained" cohort of four radiation oncologists who contoured without guidelines. Using automated planning software, the seroma target volume (STV) was expanded into a clinical target volume (CTV) and planning target volume (PTV) for each oncologist. Means and standard deviations were calculated, and two-tailed t tests were used to assess differences between the "trained" and "untrained" cohorts. In phase 2, all eight radiation oncologists were provided with the same contouring guidelines, and were asked to delineate the seroma in five new cases. Data were again analyzed to evaluate consistency between the two cohorts.

RESULTS

The "untrained" cohort contoured larger seroma volumes and had larger CTVs and PTVs compared with the "trained" cohort in three of five cases. When seroma contouring was performed after review of contouring guidelines, the differences in the STVs, CTVs, and PTVs were no longer statistically significant.

CONCLUSION

Guidelines can improve consistency among radiation oncologists performing target volume delineation for PBRT planning.

Adjuvant axillary radiotherapy for breast cancer: Is CT planning with nodal contouring better than traditional planning?

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Background: Historically, adjuvant radiotherapy planning for breast cancer has been based on clinical mark-up then subsequently bony landmarks. The objective of this study is to investigate whether individualized CT-based nodal contour guided planning of axillary fields in breast cancer improves nodal coverage and minimizes dose to normal tissues. There have been no previous studies addressing this issue. Methods: Thirty 4-field radiotherapy plans were selected as ‘traditional’ plans: 15 without nodal contours (traditional field placement) and 15 with radiation oncologists’ nodal contours. The following structures were contoured on each patient CT, regardless of previously contoured structures: level I, level II/III, supraclavicular(SCV)/infraclavicular(ICV) lymph nodes, ipsilateral brachial plexus and lung. Dose volume histograms (DVHs) of the listed contoured structures were obtained for the 30 original plans. All 30 patients were then re-planned with the same anterior dose prescription as the original plan (4000cGy/16 fractions (#) or 4500cGy/25#) but adjusted depth of midplane dose prescription based on nodal depth; MLC blocking was adjusted to the ‘study’ nodal contours. DVHs of the contoured structures for the new nodal-based plans were compared with the DVHs of the original plans, using two-tailed paired t-tests. Results: Volume receiving 90% dose (V90) was significantly improved for SCV nodes: original plan 84.67% vs nodal plan 95.76%(p=0.0005). V90 were similar for level I and level II/III nodes, but hot spots in these nodal groups were significantly hotter in the original vs nodal plan: mean hot spot for level I 120.8% vs 116.3%(p=0.0008), mean hot spot for level II/III 118.1% vs 113.2% (p=0.000003). Dose to 90% of the brachial plexus (D90) was significantly higher in the original vs nodal plan: 79.92% vs 40.92%(p=0.0028). V20 lung were not significantly different. Mean total body dose was significantly higher in the original vs nodal plan 831.8cGy vs 677.7cGy (p=0.0015). Conclusions: CT-based nodal contour guided planning significantly improves coverage of the nodes, particularly supraclavicular nodes, while markedly reducing the dose to critical normal structures, such as brachial plexus.

No significant financial relationships to disclose.

The Global Public Health Intelligence Network and early warning outbreak detection: a Canadian contribution to global public health

The recent SARS epidemic has renewed widespread concerns about the global transmission of infectious diseases. In this commentary, we explore novel approaches to global infectious disease surveillance through a focus on an important Canadian contribution to the area--the Global Public Health Intelligence Network (GPHIN). GPHIN is a cutting-edge initiative that draws on the capacity of the Internet and newly available 24/7 global news coverage of health events to create a unique form of early warning outbreak detection. This commentary outlines the operation and development of GPHIN and compares it to ProMED-mail, another Internet-based approach to global health surveillance. We argue that GPHIN has created an important shift in the relationship of public health and news information. By exiting the pyramid of official reporting, GPHIN has created a new monitoring technique that has disrupted national boundaries of outbreak notification, while creating new possibilities for global outbreak response. By incorporating news within the emerging apparatus of global infectious disease surveillance, GPHIN has effectively responded to the global media's challenge to official country reporting of outbreak and enhanced the effectiveness and credibility of international public health.

The Value of FDG Positron Emission Tomography in the Management of Patients with Breast Cancer

Increasing experience with positron emission tomography (PET) scanning in breast cancer patients is revealing a significant role for this imaging modality. This report summarizes the experience of 2-[F18]fluoro-2-deoxy-D-glucose (FDG) PET scanning in 165 breast cancer patients from the BC Cancer Agency, British Columbia, Canada, and reviews the literature on this topic. Using the database at PETSCAN Vancouver, we identified imaged patients with a diagnosis of breast cancer. We then conducted a retrospective review of these patients' BC Cancer Agency charts to extract demographic and follow-up information. Between November 2000 and March 2003 we identified 165 patients with histologically confirmed breast cancer who had undergone PET scanning, were registered at the BC Cancer Agency, and had follow-up information. The median patient age was 52 years. The sensitivity of PET in detecting axillary metastases was 28%, and the specificity was 86%. At diagnosis, 5% of patients were diagnosed with distant metastases. In patients undergoing PET scanning because of suspected recurrence, the sensitivity and specificity for detecting recurrence were 89% and 88%, respectively. Distant metastases were demonstrated in 30% of patients who were thought only to have local-regional recurrence. The results suggest that there are two clinical situations in which PET appears to be particularly valuable. The first is in the evaluation of patients who are suspected of having a tumor recurrence. The other is in identifying patients with multifocal or distant sites of malignancy who otherwise appear to have an isolated, potentially curable, local-regional recurrence.

Evolving Treatment Strategies for Inflammatory Breast Cancer: A Population-Based Survival Analysis

Purpose

To determine if mastectomy (Mx) use, chemotherapy (CT) intensity, or treatment sequence of CT, radiation therapy (RT), and Mx have improved outcome for inflammatory breast cancer (IBC).

Patients and Methods

A retrospective analysis of 485 patients with IBC diagnosed in British Columbia between 1980 and 2000 analyzed locoregional relapse-free survival (LRFS) and breast cancer–specific survival (BCSS) by treatment intent and treatment received. Curative intent was defined as delivery of more than four cycles of anthracycline-based CT plus locoregional RT in patients without distant metastases.

Results

Median follow-up among survivors was 6.5 years. Median BCSS was 1.0 and 3.2 years for patients with distant metastases at diagnosis or those who were curatively treated, respectively. Among patients treated curatively (n = 308), there were no significant differences in LRFS or BCSS with timing of Mx before or after CT/RT, time between diagnosis and RT, or the sequence of RT and CT. Patients receiving more intensive CT had improved 10-year BCSS compared with standard CT (43.7% v 26.3%; P = .04). Ten-year LRFS for patients having Mx after CT, Mx before CT, and without Mx was 62.8%, 58.6%, and 34.4%, respectively (P = .0001); the corresponding 10-year BCSS was 36.9%, 19.9%, and 22.5%, respectively (P = .005). On multivariate analysis, Mx was associated with improved LRFS (P = .04). Independent prognostic factors for BCSS were menopausal status (P = .02), estrogen receptor status (P = .02), and CT type (P = .05).

Conclusion

This retrospective analysis suggested that mastectomy, in conjunction with CT and RT, seemed to enhance locoregional control, whereas modern CT regimens seemed to improve BCSS.

Locoregional radiation therapy in patients with high-risk breast cancer receiving adjuvant chemotherapy: 20-year results of the British Columbia randomized trial

BACKGROUND

The British Columbia randomized radiation trial was designed to determine the survival impact of locoregional radiation therapy in premenopausal patients with lymph node-positive breast cancer treated by modified radical mastectomy and adjuvant chemotherapy. Three hundred eighteen patients were assigned to receive no further therapy or radiation therapy (37.5 Gy in 16 fractions). Previous analysis at the 15-year follow-up showed that radiation therapy was associated with a statistically significant improvement in breast cancer survival but that improvement in overall survival was of only borderline statistical significance. We report the analysis of data from the 20-year follow-up.

METHODS

Survival was analyzed by the Kaplan-Meier method. Relative risk estimates were calculated by the Wald test from the proportional hazards regression model. All statistical tests were two-sided.

RESULTS

At the 20 year follow up (median follow up for live patients: 249 months) chemotherapy and radiation therapy, compared with chemotherapy alone, were associated with a statistically significant improvement in all end points analyzed, including survival free of isolated locoregional recurrences (74% versus 90%, respectively; relative risk [RR] = 0.36, 95% confidence interval [CI] = 0.18 to 0.71; P = .002), systemic relapse-free survival (31% versus 48%; RR = 0.66, 95% CI = 0.49 to 0.88; P = .004), breast cancer-free survival (48% versus 30%; RR = 0.63, 95% CI = 0.47 to 0.83; P = .001), event-free survival (35% versus 25%; RR = 0.70, 95% CI = 0.54 to 0.92; P = .009), breast cancer-specific survival (53% versus 38%; RR = 0.67, 95% CI = 0.49 to 0.90; P = .008), and, in contrast to the 15-year follow-up results, overall survival (47% versus 37%; RR = 0.73, 95% CI = 0.55 to 0.98; P = .03). Long-term toxicities, including cardiac deaths (1.8% versus 0.6%), were minimal for both arms.

CONCLUSION

For patients with high-risk breast cancer treated with modified radical mastectomy, treatment with radiation therapy (schedule of 16 fractions) and adjuvant chemotherapy leads to better survival outcomes than chemotherapy alone, and it is well tolerated, with acceptable long-term toxicity.

The problem of evidence-based medicine: directions for social science

Evidence-based medicine (EBM) is arguably the most important contemporary initiative committed to reshaping biomedical reason and practice. The move to establish scientific research as a fundamental ground of medical decision making has met with an enthusiastic reception within academic medicine, but has also generated considerable controversy. EBM and the broader forms of evidence-based decision making it has occasioned raise provocative questions about the relation of scientific knowledge to social action across a variety of domains. Social science inquiry about EBM has not yet reached the scale one might expect, given the breadth and significance of the phenomenon. This paper contributes reflections, critique and analysis aimed at helping to build a more robust social science investigation of EBM. The paper begins with a "diagnostics" of the existing social science literature on EBM, emphasizing the possibilities and limitations of its two central organizing analytic perspectives: political economy and humanism. We further explore emerging trends in the literature including a turn to original empirical investigation and the embrace of "newer" theoretical resources such as postmodern critique. We argue for the need to move the social inquiry of EBM beyond concerns about rationalization and the potential erasure of the patient and, to this end, suggest new avenues of exploration. The latter include analysis of clinical epidemiology and clinical reason as the discursive preconditions of EBM, the role of the patient as a site for the production of evidence, and the textually mediated character of EBM.