Abstract P4-02-01: Normalization of compression-induced hemodynamics in patients responding to neoadjuvant chemotherapy using dynamic tomographic optical breast imaging (TOBI)

Background: Diffuse optical imaging using near-infrared light is emerging as a promising non-invasive method for breast neoadjuvant chemotherapy (NAC) monitoring and outcome prediction. While the majority of published studies rely on “static” assessments of tissue oxy- and deoxy- hemoglobin concentration, we have focused on extending diffuse optical tomography to capture hemodynamic changes driven by fractional mammographic compression. These hemodynamic changes are governed by the interplay of tissue biomechanics and oxygen metabolism, and thus form a novel class of optical dynamic biomarkers of breast pathology. In this study we seek to evaluate the predictive value of these biomarkers with respect to treatment outcome.

Methods: We are conducting a pilot feasibility study in female patients with unilateral locally advanced breast cancer undergoing standard of care NAC. In this analysis we focused on pre-treatment and day 30 post-treatment dynamic TOBI scans. Both breasts are compressed in turn to 4-8 lbs of force (depending on size) and optical images are acquired every 2 seconds over 2 minutes. We compute the time course of oxy (HbO), deoxy (HbR)and total (HbT) hemoglobin concentration as well as the hemoglobin oxygen saturation (SO2). Regions of interest are defined in the optical images to correspond to the radiology identified tumor location, and the healthy tissue in the same breast, respectively. We compare the time courses in the two regions at baseline, and 30 days after initiation of treatment.

Results: In this analysis we present results from 6 patients including 3 responders (defined as greater than 50% reduction in the largest tumor axis from baseline imaging and final pathology) and 3 non-responders. As the compression plates are held in place the tissue collagen matrix begins to stretch, effectively reducing the compression force. At baseline, all patients exhibited an initial decrease in HbT, HbO and SO2. In the tumor area, this was followed by little or no recovery as the compression plates were held in place. The normal tissue, in contrast, began recovering almost immediately. At day 30, the tumor area in the non-responders displayed similar time-course characteristics to day 0. Interestingly, however, at day 30 responders had a very similar time course in both the tumor and normal area, characterized by a slow recovery that begins soon after the compression plates stop moving. Table 1 summarizes the changes in total hemoglobin at t = 90 seconds.

Conclusions: At day 30 after NAC, responding tumors demonstrated “normalization” of compression induced hemodynamics in the tumor area whereas nonresponding tumors did not. This encouraging data suggests that dynamic TOBI can easily detect changes due to treatment. Complete analysis of the patient data to assess the outcome prediction ability using this novel optical imaging technology is ongoing.

Compression induced changes in total hemoglobin a t = 90 seconds during compressionΔHbTtumor- ΔHbTnormal (μM)RespondersNon-RespondersDay 0-0.65 ± 0.21-0.82 ± 0.24Day 300.10 ± 0.24-1.13 ± 0.74

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-02-01.

Abstract P3-06-27: Dynamic tomographic optical breast imaging (TOBI) to monitor response to neoadjuvant therapy in breast cancer

Background: Near-infrared optical measurements have been recently shown to offer a promising non-invasive way for monitoring breast neoadjuvant chemotherapy (NAC) and predicting outcome. In particular, snapshots of tissue oxy and deoxy-hemoglobin concentration as well as water and lipid content have been demonstrated to be sensitive to therapy-induced changes. In this study, we extend optical measurements to capture additional hemodynamic and metabolic biomarkers revealed by dynamically imaging breast tissue during fractional mammographic compression. Using our dynamic tomographic optical breast imaging (TOBI) system we evaluate the early prediction performance of this advanced technology.

Methods: We are conducting a pilot feasibility study in female patients with unilateral locally advanced breast cancer undergoing standard-of-care NAC. Pre-treatment and day 7 post-treatment TOBI scans are obtained, with additional (optional) scans on day 1 of each subsequent chemotherapy cycle. Both breasts are compressed in turn to 4–8 lbs of force, and optical images are acquired once every 2 seconds over two minutes. Time-resolved oxy-(HbO), deoxy-(HbR), and total-(HbT) hemoglobin concentration and hemoglobin oxygen saturation (SO2) are calculated. The compression-induced rate of change of HbT correlates with changes in tissue blood volume indicative of biomechanical properties. The evolution of tissue SO2 is modeled to obtain an index of the ratio of oxygen metabolism to blood flow. Therapy induced changes are quantified, and comparisons between changes in responders vs. non-responders are performed (response is defined here as >50% reduction in the largest tumor diameter).

Results: We have enrolled 20 patients so far, of which 90% (N = 18) completed both the day 0 and day 7 scans. 17 patients have undergone surgery at this point. We focused our initial analysis on 5 HER2+ patients, of which two were non-responders, and three were responders according to our criteria. Four patients received taxol+herceptin+lapatinib, while the other received taxol+lapatinib only. In this small subgroup, the non-responders had an average increase of 1% in total hemoglobin concentration (HbT) from day 0 to day 7, while the responders had an average 12% decrease in HbT, respectively. We also noted different trends in the evolution of the tissue oxygen consumption to blood flow ratio, which increased 32% in non-responders from day 0 to day 7, while decreasing 11% in responders.

Conclusions: The large percentage of enrolled patients that completed both initial scans demonstrates the feasibility of using dynamic optical breast tomography for breast neoadjuvant chemotherapy monitoring. Results in a small cohort of 5 HER2+ patients suggested a decreasing trend in HbT for responders as observed by previous studies. We also report for the first time an increase in the metabolic ratio of oxygen consumption to blood flow in non-responders vs. a decrease in responders. These initial results of our on-going study suggest that dynamic TOBI can detect changes due to treatment and may have predictive value for the treatment outcome and supports further studies of this non-invasive and portable tool for chemotherapy monitoring.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-06-27.

Prediction of late recurrences by breast cancer index in the NCIC CTG MA.17 cohort

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Background: The MA.17 trial demonstrated that extended adjuvant endocrine therapy with letrozole after 5-y of tamoxifen markedly reduced the risk of recurrence in women with ER+ early stage breast cancer. This trial provides an opportunity to assess the ability of biomarkers to predict late recurrences in ER+ breast cancer. The Breast Cancer Index (BCI), a continuous risk index based on the combination of HOXB13:IL17BR (H:I) and the molecular grade index (MGI), estimates the individual risk of recurrence in ER+ breast cancer patients. In this study, the prognostic utility of BCI to predict late recurrences was examined.

Methods: FFPE tumor blocks were collected from patients who experienced a breast cancer recurrence up to unblinding of MA.17. Controls were matched 2:1 for age, tumor size, nodal status and prior chemotherapy, and were disease free for longer than cases. All cases were reviewed for standard histopathology and evaluated using the real-time RT-PCR BCI assay.

Results: Patient characteristics for the case-control study were similar to that from the overall study. Characteristics for cases (N=83) and controls (N=166) were not significantly different except for treatment. A higher percentage of controls compared to cases tended to be categorized as low risk by BCI (58% vs 43%), while a lower percentage of controls than cases tended to be categorized as high risk by BCI (34% vs 24%). In univariate analysis, treatment, BCI, H:I and HOXB13, but not tumor grade or MGI, were significant predictors of late recurrence. After adjusting for standard variables (age, tumor grade and treatment), BCI (OR 2.37; P=0.03), H:I (OR 2.55; P=0.04) and HOXB13 (OR 1.35; P=0.02) remained significant predictors of recurrence. HOXB13 expression at diagnosis predicted patient benefit from extended endocrine therapy with letrozole.

Conclusions: In this case-controlled study, the data demonstrate that BCI is a significant predictor of late recurrences in ER+ patients following 5-y of tamoxifen. The prognostic performance of BCI to predict late recurrences was largely dependent on HOXB13 expression. The integration of H:I and MGI within BCI provides prognostic utility for both early and late recurrences.

Functional metabolic tomographic optical breast imaging (TOBI) to monitor response to neoadjuvant therapy in breast cancer

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Background: Recent studies using near-infrared optical measurements in breast tumors have demonstrated the promise of early monitoring of neoadjuvant chemotherapy (NAC) to predict outcome. Technologies to date have focused primarily on static measurements. Dynamic optical imaging, in conjunction with fractional mammographic compression, offers access to multiple functional and metabolic tissue biomarkers that may be used to predict treatment response. We have developed a novel tomographic optical breast imaging (TOBI) device to evaluate the early (day 7) prediction performance of this advanced technology.

Methods: We are conducting a pilot feasibility study in female patients with unilateral locally advanced breast cancer undergoing standard-of-care NAC. Pre-treatment and day 7 post-treatment TOBI scans are obtained, with additional scans on day 1 of each subsequent chemotherapy cycle. The affected and contralateral normal breasts are compressed to 6-8 lbs of force and optical images are acquired once every 2 seconds for two minutes. Time-resolved oxy-(HbO), deoxy-(HbR), and total-(HbT) hemoglobin concentration and hemoglobin oxygen saturation (SO2) are calculated. The compression-induced rate of change of HbT correlates with changes in tissue blood volume indicative of biomechanical properties and the evolution of tissue SO2 estimates tissue metabolism.

Results: We report initial data from two patients. One patient had a near-pathologic complete response (responder) and showed 21% and 23% decreases in HbT and HbR, respectively. The second patient had no significant response (non-responder) and had 2% and 1% decreases in HbT and HbR, respectively. Interestingly, the responder showed a dynamic decrease in HbT during compression in the tumor region at day 0 that disappeared at day 7, while the non-responder had similar rates of HbT change at both scans.

Conclusions: We demonstrate for the first time the feasibility of dynamic optical breast tomography and show that optically derived parameters may be sensitive to therapyinduced changes in breast cancer. These dynamic measurements may provide novel insight into the physiologic changes in breast tumors during treatment.

Abstract P3-10-26: Quantitative Protein and Gene Expression Biomarkers of Tamoxifen and Letrozole Recurrence in the NCIC CTG MA.17 Cohort

Background: The MA.17 study showed that extended adjuvant endocrine therapy with letrozole (LET) after completing 5 years of tamoxifen (TAM) markedly reduced the risk of recurrence in women with ER+ early stage breast cancer and improved overall survival in women presenting with node +ve disease. The HOXB 13:IL17BR gene expression ratio (signature) has been shown to predict outcome in breast cancer patients treated with adjuvant tamoxifen monotherapy and provides additional information beyond that from known positive (ER and PR) and negative (Her-1 and Her-2) predictors of responsiveness to tamoxifen in node-ve women. We report a case control evaluation of the Breast Cancer Index (BCI; bioTheranostics, Inc.), which combines the HOXB13 and IL17BR twogene and the molecular grade index (MGI) gene expression signatures, with respect to distinguishing which patients are at risk of late recurrences and who would respond to extended endocrine therapy with LET. The prognostic and predictive utility of quantitative immunofluorescence of ER, PR, Her-2, tumor aromatase, COX-2, GATA3 and Nat1 in the TAM-PLACEBO and the TAM-LET cohorts will also be evaluated and compared to results derived by standard immunohistochemistry. Methods: FFPE tumor blocks were collected from patients who experienced a breast cancer recurrence up to unblinding of MA.17. Controls were matched 2:1 for age, tumor size, lymph node status, and prior chemotherapy, and were all disease free for longer than cases. All cases were reviewed for standard histopathology by two independent pathologists. RNA was extracted, amplified, converted to cDNA and subjected to RT-PCR with primers and probes to HOXB13, IL17BR, BUB1A, CENPA, NEK2, RACGAP1 and RRM2. ER, PR HER1, HER2, COX2, Aromatase, GATA3 and NAT1 will be analyzed by routine IHC techniques and by immunoflourescent Automated Quantitative Analysis (AQuA).

Results: 105 cases and 210 matched controls are available for evaluation. All sections are under review and tissue microarrays have been performed on all cases and controls. Detailed results on the BCI and ER, PR, Her-2 will be available at the SABCS.

Discussion: MA.17 has shown that extended adjuvant endocrine therapy after tamoxifen is effective at preventing disease recurrence given for an additional 5 years. Numerous clinical trials are exploring whether extending AIs will show this benefit, and there is an increasing need to improve the therapeutic index by distinguishing those at risk from those who are not. It is also important to determine which patients will benefit from the therapy and which will recur without benefit. The latter patients could be triaged to clinical trials of novel therapies to overcome endocrine resistance. This study will help to define these issues and pave the way for more effective selection of specific patients for adjuvant endocrine strategies.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-26.

A prospective multi-center ovarian cancer screening study in women at increased risk

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Background: No proven ovarian cancer (OC) screening strategy exists for women who are at increased risk for the disease. A risk of ovarian cancer algorithm (ROCA) using serial CA125 values has previously shown greater positive predictive value (PPV) and sensitivity than a single CA125 in screening women at general population risk. We hypothesized that using ROCA would yield a reasonable PPV for ovarian cancer screening in a cohort at increased risk. Methods: Between 7/2001 and 9/2006, 25 sites (14 Cancer Genetics Network, 3 ovarian SPOREs, 1 EDRN, 7 others) prospectively enrolled patients. Inclusion criteria included: among self, 1° or 2° relatives in same lineage either (i) BRCA1/2 mutation, or (ii) two of OC or early onset (age = 50) breast cancer (BC), or (iii) Ashkenazi ethnicity and 1 of OC or BC. A previous diagnosis of OC excluded subjects. Subjects underwent CA125 every 3 months and the risk of having ovarian cancer based on the CA125 profile was recalculated after each test. ROCA referred subjects with risk > 1% to ultrasound (US), and risk > 10% additionally to a gynecologic oncologist. Objectives included PPV for study indicated surgery, sensitivity, and compliance. Sample size was chosen to observe 8 OC endpoints with a power of 80% to rule out PPV = 10% if the true PPV = 20%. Results: 2,343 high risk women enrolled, with 6,284 women years of screening and 19,549 CA125s obtained. There were 628 (10%/yr) referrals to US with 414 US performed. 38 women underwent study indicated surgeries. 9 OCs were identified during screening, 3 were prevalent (1 early, 2 late stage), and 6 were incident (5/6 = 83% early, 1 late). 3 of the 6 incident cases were found on prophylatic oophorectomy in early stage. ROCA detected 2 in early stage of remaining 3 incident cases, and 3 of 3 prevalent cases. The PPV was 5/38 = 13% (95% CI 4.4%, 28%) and sensitivity was 5/6 = 83%, CI (36%, 99%). There was high compliance with CA125 testing throughout study, with 84%, 85%, 85%, 82% subjects returning within 1 month of schedule for first 4 tests. Conclusions: Frequent CA125 testing using ROCA results in an acceptable PPV and high compliance in a cohort of women at increased risk for OC. A definitive screening study (= 30 incident cases) using ROCA with serial CA125 and possibly additional markers is required to define sensitivity for early stage OC.

[Table: see text]

Hypothalamic/pituitary function following high-dose conformal radiotherapy to the base of skull: demonstration of a dose-effect relationship using dose-volume histogram analysis

PURPOSE

To evaluate the incidence and pattern of hypopituitarism from hypothalamic (HT) and pituitary gland (PG) damage following high-dose conformal fractionated proton-photon beam radiotherapy (PPRT) to the base of skull (BOS) region in adults. The relationship between dose, volume, and PG function is explored.

METHODS AND MATERIALS

Between May 1982 to October 1997, 107 adults with non-PG and non-HT neoplasms (predominantly chordoma and chondrosarcomas) of the BOS were treated with PPRT after subtotal resection(s). The median age was 41.2 years (range, 17-75) with 58 males and 49 females. Median prescribed target dose was 68.4 cobalt gray equivalent (CGE) (range, 55.8-79 CGE) at 1.80-1.92 CGE per fraction per day (where CGE = proton Gy x 1.1). The HT and PG were outlined on planning CT scans to allow dose-volume histograms (DVH) analysis. All patients had baseline and follow-up clinical testing of anterior and posterior pituitary function including biochemical assessment of thyroid, adrenal, and gonadal function, and prolactin secretion.

RESULTS

The 10-year actuarial overall survival rate was 87%, with median endocrine follow-up time of 5.5 years, thus the majority of patients were available for long-term follow-up. Five-year actuarial rates of endocrinopathy were as follows: 72% for hyperprolactinemia, 30% for hypothyroidism, 29% for hypogonadism, and 19% for hypoadrenalism. The respective 10-year endocrinopathy rates were 84%, 63%, 36%, and 28%. No patient developed diabetes insipidus (vasopressin deficiency). Growth hormone deficiency was not routinely followed in this study. Minimum target dose (Dmin) to the PG was found to be predictive of endocrinopathy: patients receiving 50 CGE or greater at Dmin to the PG experiencing a higher incidence and severity (defined as the number of endocrinopathies occurring per patient) of endocrine dysfunction. Dmax of 70 CGE or greater to the PG and Dmax of 50 CGE or greater to the HT were also predictive of higher rates of endocrine dysfunction.

CONCLUSION

Radiation-induced damage to the HT & PG occurs frequently after high-dose PPRT to the BOS and is manifested by anterior pituitary gland dysfunction. Hyperprolactinemia was detected in the majority of patients. Posterior pituitary dysfunction, represented by vasopressin activity with diabetes insipidus, was not observed in this dose range. Limiting the dose to the HT and PG when feasible should reduce the risk of developing clinical hypopituitarism.

Evidence for an association between cutaneous melanoma and non-Hodgkin lymphoma

BACKGROUND

Over the past 2 decades both cutaneous melanoma (CM) and non-Hodgkin lymphoma (NHL) incidence rates have increased substantially. One approach to better understanding the etiologic basis for these increases is to examine the risk of NHL in CM survivors and the risk of CM in NHL survivors.

METHODS

To explore the possible association between CM and NHL, the authors followed cohorts of CM and NHL patients registered through the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program between 1973 and 1996 and identified patients who developed CM after NHL and NHL after CM. The number of observed cases then were compared with the number of expected cases to see if CM survivors were at an increased risk of NHL or if NHL survivors were at an increased risk of CM.

RESULTS

Between 1973 and 1996, 54,803 CM patients and 62,597 NHL patients who met the authors' inclusion criteria were identified through SEER. The authors found statistically significant elevated risks of NHL among CM survivors (standardized incidence ratio [SIR], 1.42; 95% confidence interval [CI], 1.23-1.63) and CM among NHL survivors (SIR, 1.75; 95% CI, 1.48-2.07).

CONCLUSIONS

These results support an association between CM and NHL. Although detection bias and posttherapy effects may explain part of this association, shared genetic or etiologic factors, such as sunlight exposure, also may play a role.

Bronchioloalveolar carcinoma of the lung: recurrences and survival in patients with stage I disease

OBJECTIVES

The aim of our study was to retrospectively compare the patient characteristics, the frequency and pattern of recurrent disease, and survival in patients with stage I bronchioloalveolar carcinoma and adenocarcinoma of the lung.

METHODS

Patients with stage I bronchioloalveolar carcinoma or adenocarcinoma other than bronchioloalveolar carcinoma resected between 1984 and 1992 with adequate clinical follow-up were studied. The clinical characteristics of the patients, extent of initial surgical resection, sites of recurrent disease, and overall survival were examined and compared between the 2 groups. The median follow-up for patients with bronchioloalveolar carcinoma and adenocarcinoma was 6.2 years and 5.9 years, respectively.

RESULTS

A total of 138 patients were identified. Thirty-three patients had bronchioloalveolar carcinoma and 105 patients had adenocarcinoma. Eleven (33%) of the patients with bronchioloalveolar carcinoma had never smoked cigarettes versus 9 (9%) of the patients with adenocarcinoma (P =.0036). There were no significant differences between patients with bronchioloalveolar carcinoma and adenocarcinoma in sex distribution and overall recurrence rate. Of the 12 patients with recurrent bronchioloalveolar carcinoma, 1 patient (8%) had extrathoracic disease develop at the site of first recurrence compared with 49% of patients with recurrent adenocarcinoma (P <.001). The 5-year survival in patients with bronchioloalveolar carcinoma and in those with adenocarcinoma was 83% and 63%, respectively (P =.04).

CONCLUSIONS

Stage I bronchioloalveolar carcinoma is more likely to occur in nonsmokers. Survival is longer in patients with bronchioloalveolar carcinoma. Further research is warranted to define the etiology, clinical course, and molecular abnormalities in patients with bronchioloalveolar carcinoma to generate more effective therapeutic approaches.

A proportional hazards model for multivariate interval-censored failure time data

This paper focuses on the methodology developed for analyzing a multivariate interval-censored data set from an AIDS observational study. A purpose of the study was to determine the natural history of the opportunistic infection cytomeglovirus (CMV) in an HIV-infected individual. For this observational study, laboratory tests were performed at scheduled clinic visits to test for the presence of the CMV virus in the blood and in the urine (called CMV shedding in the blood and urine). The study investigators were interested in determining whether the stage of HIV disease at study entry was predictive of an increased risk for CMV shedding in either the blood or the urine. If all patients had made each clinic visit, the data would be multivariate grouped failure time data and published methods could be used. However, many patients missed several visits, and when they returned, their lab tests indicated a change in their blood and/or urine CMV shedding status, resulting in interval-censored failure time data. This paper outlines a method for applying the proportional hazards model to the analysis of multivariate interval-censored failure time data from a study of CMV in HIV-infected patients.

Correcting for noncompliance and dependent censoring in an AIDS Clinical Trial with inverse probability of censoring weighted (IPCW) log-rank tests

AIDS Clinical Trial Group (ACTG) randomized trial 021 compared the effect of bactrim versus aerosolized pentamidine (AP) as prophylaxis therapy for pneumocystis pneumonia (PCP) in AIDS patients. Although patients randomized to the bactrim arm experienced a significant delay in time to PCP, the survival experience in the two arms was not significantly different (p = .32). In this paper, we present evidence that bactrim therapy improves survival but that the standard intent-to-treat comparison failed to detect this survival advantage because a large fraction of the subjects either crossed over to the other therapy or stopped therapy altogether. We obtain our evidence of a beneficial bactrim effect on survival by artificially regarding the subjects as dependently censored at the first time the subject either stops or switches therapy; we then analyze the data with the inverse probability of censoring weighted Kaplan-Meier and Cox partial likelihood estimators of Robins (1993, Proceedings of the Biopharmaceutical Section, American Statistical Association, pp. 24-33) that adjust for dependent censoring by utilizing data collected on time-dependent prognostic factors.

Low prevalence of germline CDKN2A and CDK4 mutations in patients with early-onset melanoma

BACKGROUND

In patients with cutaneous melanoma, early age at disease onset is characteristic in familial cases and in individuals with multiple primary melanomas. Both subsets of patients with melanoma are at risk for harboring germline CDKN2A or CDK4 mutations.

OBJECTIVE

We set out to prospectively determine the prevalence of CDKN2A and CDK4 mutations in a group of young patients with melanoma.

DESIGN

We prospectively screened 913 patients over a 6-month period and identified 519 patients with invasive melanomas. We invited 172 patients with melanoma who were younger than 40 years to participate in the study, and 49 patients consented and donated peripheral blood samples. Forty-nine percent (n = 24) of our patients developed cutaneous melanoma before the age of 30 years.

SETTING

A melanoma clinic in the Boston, Mass, area.

MAIN OUTCOME MEASURE

We used a combination of single-strand conformation analysis and direct sequencing of samples of peripheral blood leukocyte DNA to search for mutations in exons 1alpha, 1beta, 2, and 3 of CDKN2A and in exon 2 of CDK4.

RESULTS

The mean and median ages at diagnosis in our group were 30 and 32 years, respectively. Among a group of 49 patients, we detected 1 (2%; 95% confidence interval, 0.07%-10.8%) Met 53 Ile CDKN2A mutation, which was found in a patient with a strong family history of melanoma. This alteration has been previously shown to impair p16 function. One patient had an Ala 148 Thr change in CDKN2A, which has also been shown to be a polymorphism. We also detected a sequence polymorphism (in the 3' untranslated region [3'UTR] of CDKN2A) in 27% of our patients. A similar incidence of this 3'UTR polymorphism was observed in a control population. We found no CDK4 mutations.

CONCLUSIONS

Germline CDKN2A and CDK4 mutations are not common in patients who develop melanoma at an early age. This finding contrasts with other cancer-predisposition syndromes, in which there is an increased incidence of germline mutations among young patients. Selection of patients with melanoma for genetic testing based solely on age at onset may not be warranted at the current time.

Predictors of skeletal complications in patients with metastatic breast carcinoma

BACKGROUND

The high rate of incidence of skeletal complications in women with metastatic breast carcinoma appears to contribute significantly to their morbidity. Although recent trials have demonstrated the efficacy of bisphosphonates in preventing skeletal complications in selected patients, to the authors' knowledge the incidence rate of skeletal complications in an unselected population of women with metastatic breast carcinoma is unknown. The current study was designed to examine the incidence rate of skeletal complications in a large unselected group of women with metastatic breast carcinoma to determine predictors of these complications.

METHODS

All women (n = 718) diagnosed with metastatic breast carcinoma between 1981-1991 at the study institution were studied retrospectively.

RESULTS

Greater than 50% of the women developed skeletal complications; among these women, 51% had > 1 complication. Approximately 80% of those with bone-limited disease at the time of diagnosis developed complications, as did 60% of those with bone and visceral disease and 21% of those with no bone disease. By univariate analysis, the site of initial metastatic disease, abnormal alkaline phosphatase, and a disease free interval of < 3 years were predictive of skeletal complications. Multivariate analysis revealed that bone involvement at the time of diagnosis was predictive of subsequent skeletal complications.

CONCLUSIONS

In this large retrospective study with extensive follow-up, skeletal complications were extremely common and repetitive, although complications predated patient death by >/= 1 year in the group of women presenting with any bone disease. The presence of bone disease at the time of initial presentation was predictive of skeletal complications. In this group of patients, the authors were unable to identify a subgroup with a low rate of skeletal complications.

Thymosin beta-15 predicts for distant failure in patients with clinically localized prostate cancer-results from a pilot study

OBJECTIVES

To report the results of a pilot study on the prognostic value of a newly identified actin-binding protein, thymosin beta-15 (Tbeta15), in predicting prostate-specific antigen (PSA) and bone failure in patients with Gleason 6/10 clinically localized prostate cancer.

METHODS

Thirty-two patients (median age 70 years) with clinically localized, moderately differentiated (Gleason 6/10) prostate cancer treated by external beam radiotherapy alone (68.4 Gy) with available paraffin blocks at the Massachusetts General Hospital were evaluated for this pilot study. All patients had clinical Stage M0 disease at initial presentation, which was documented by bone scan (T1c-4,NX). Their corresponding biopsy specimens were stained immunohistochemically for Tbeta15, which was then correlated with the clinical outcome in a blinded manner. The median follow-up was 6 years (range 1 to 19) for all of the patients.

RESULTS

The outcomes of the 32 patients can be grouped into three categories: patients with no evidence of disease (n = 11), patients with PSA failure without documented bone failure (n = 11), and patients with PSA failure and documented bone failure (n = 10). Tbeta15 staining intensity strongly correlated with clinical outcome. Of those patients whose specimens stained 3+ (strongest staining), 62% developed bone failure compared with 13% of those patients whose specimens stained 1+ (weakest staining) (P = 0.01). The 5-year freedom from PSA failure was only 25% for those patients with 3+ staining compared with 83% for those with 1+ staining (P = 0.02).

CONCLUSIONS

The results of this pilot study have demonstrated that Tbeta15 staining intensity may be a potentially important marker to identify high-risk patients with moderately differentiated, clinically localized prostate cancer.

Stage III thymoma: pattern of failure after surgery and postoperative radiotherapy and its implication for future study

PURPOSE

With the conventional approach of surgery and postoperative radiotherapy for patients with Masaoka Stage III thymoma, progress has been slow for an improvement in the long-term survival rate over the past 20 years. The objective of this study was to evaluate the pattern of failure and survival after surgery and postoperative radiotherapy in Stage III thymoma and search for a new direction for better therapy outcome.

METHODS AND MATERIALS

Between 1975 and 1993, 111 patients with thymoma were treated at Massachusetts General Hospital. Of these, 32 patients were determined to have Masaoka Stage III thymoma. The initial treatment included surgery for clinically resectable disease in 25 patients and preoperative therapy for unresectable disease in 7 patients. Surgical procedure consisted of thymectomy plus resection of involved tissues. For postoperative radiotherapy (n = 23), radiation dose consisted of 45-50 Gy for close resection margins, 54 Gy for microscopically positive resection margins, and 60 Gy for grossly positive margins administered in 1.8 to 2.0 Gy of daily dose fractions, 5 fractions a week, over a period of 5 to 6.6 weeks. In preoperative radiotherapy, a dose of 40 Gy was administered in 2.0 Gy of daily dose fractions, 5 days a week. For patients with large tumor requiring more than 30% of total lung volume included in the target volume (n = 3), a preoperative radiation dose of 30 Gy was administered and an additional dose of 24-30 Gy was given to the tumor bed region after surgery for positive resection margins.

RESULTS

Patients with Stage III thymoma accounted for 29% (32/111 patients) of all patients. The median age was 57 years with a range from 27 to 81 years; gender ratio was 10:22 for male to female. The median follow-up time was 6 years. Histologic subtypes included well-differentiated thymic carcinoma in 19 (59%), high-grade carcinoma in 6 (19%), organoid thymoma in 4 (13%), and cortical thymoma in 3 (9%) according to the Marino and Müller-Hermelink classification. The overall survival rates were 71% and 54% at 5 and 10 years, respectively. Ten of the 25 patients who were subjected to surgery as initial treatment were found to have incomplete resection by histopathologic evaluation. The 5- and 10-year survival rates were 86% and 69% for patients (n = 15) with clear resection margins as compared with 28% and 14% for those (n = 10) with incomplete resection margins even after postoperative therapy, p = 0.002. Survival rates at 5 and 10 years were 100% and 67% for those with unresectable disease treated with preoperative radiation (n = 6) and subsequent surgery (n = 3). Recurrence was noted in 12 of 32 patients and 11 of these died of recurrent thymoma. Recurrences at pleura and tumor bed accounted for 77% of all relapses, and all pleural recurrences were observed among the patients who were treated with surgery initially.

CONCLUSION

Incomplete resection leads to poor results even with postoperative radiotherapy or chemoradiotherapy in Stage III thymoma. Pleural recurrence is also observed more often among patients treated with surgery first. These findings suggest that preoperative radiotherapy or chemoradiotherapy may result in an increase in survival by improving the rate of complete resection and reducing local and pleural recurrences.

Serotonin function following remission from bulimia nervosa

Abnormal serotonergic regulation in bulimia nervosa is thought to contribute to recurrent binge eating, depressed mood, and impulsivity. To follow-up on previous studies showing decreased neuroendocrine responses in symptomatic patients, this study assessed serotonin-mediated prolactin responses in individuals who had remitted from bulimia nervosa. Subjects included 21 women with a history of bulimia nervosa and 21 healthy female controls, as well as an additional comparison group of 19 women with current bulimia nervosa. Placebo-controlled neuroendocrine response studies utilized a single oral dose (60 mg) of the indirect serotonin agonist d,l-fenfluramine. For the bulimia nervosa remitted group, the fenfluramine-stimulated elevation in serum prolactin concentration was not significantly different from the response in healthy controls, but was significantly larger than the response in patients with current bulimia nervosa (p < .01). These findings suggest that diminished serotonergic neuroendocrine responsiveness in bulimia nervosa reflects a state-related abnormality. The results are discussed in relationship to recent reports indicating that some alterations in central nervous system serotonin regulation may persist in symptomatically recovered individuals.

A non-parametric maximum likelihood estimator for bivariate interval censored data

We derive a non-parametric maximum likelihood estimator for bivariate interval censored data using standard techniques for constrained convex optimization. Our approach extends those taken for univariate interval censored data. We illustrate the estimator with bivariate data from an AIDS study.

An extension of Kendall's coefficient of concordance to bivariate interval censored data

Non-parametric tests of independence, as well as accompanying measures of association, are essential tools for the analysis of bivariate data. Such tests and measures have been developed for uncensored and right censored failure time data, but have not been developed for interval censored failure time data. Bivariate interval censored data arise in AIDS studies in which screening tests for early signs of viral and bacterial infection are done at clinic visits. Because of missed clinic visits, the actual times of first positive screening tests are interval censored. To handle such data, we propose an extension of Kendall's coefficient of concordance. We apply it to data from an AIDS study that recorded times of shedding of cytomegalovirus (CMV) and times of colonization of mycobacterium avium complex (MAC). We examine the performance of our proposed measure through a simulation study.

Applying the Cox proportional hazards model for analysis of latency data with interval censoring

The latency time of an infectious disease is defined as the time from infection to disease onset. This paper applies the proportional hazards model to estimate the effect of covariates on latency when the time of disease onset is exact or right-censored but the time of infection is interval-censored. We use a Monte Carlo EM algorithm to estimate parameters of the joint distribution of infection times and latency times. At each EM iteration, exact infection times are multiply imputed from the density determined by the parameters of the infection and latency time distributions. The methodology is tested using a simulation study and is applied to data from a cohort of haemophiliacs with HIV disease.

Combining mortality and longitudinal measures in clinical trials

Clinical trials often assess therapeutic benefit on the basis of an event such as death or the diagnosis of disease. Usually, there are several additional longitudinal measures of clinical status which are collected to be used in the treatment comparison. This paper proposes a simple non-parametric test which combines a time to event measure and a longitudinal measure so that a substantial treatment difference on either of the measures will reject the null hypothesis. The test is applied on AIDS prophylaxis and paediatric trials.

Combining mortality and longitudinal measures in clinical trials

Clinical trials often assess therapeutic benefit on the basis of an event such as death or the diagnosis of disease. Usually, there are several additional longitudinal measures of clinical status which are collected to be used in the treatment comparison. This paper proposes a simple non-parametric test which combines a time to event measure and a longitudinal measure so that a substantial treatment difference on either of the measures will reject the null hypothesis. The test is applied on AIDS prophylaxis and paediatric trials.

Applying the Cox proportional hazards model when the change time of a binary time-varying covariate is interval censored

This paper develops methodology for estimation of the effect of a binary time-varying covariate on failure times when the change time of the covariate is interval censored. The motivating example is a study of cytomegalovirus (CMV) disease in patients with human immunodeficiency virus (HIV) disease. We are interested in determining whether CMV shedding predicts an increased hazard for developing active CMV disease. Since a clinical screening test is needed to detect CMV shedding, the time that shedding begins is only known to lie in an interval bounded by the patient's last negative and first positive tests. In a Cox proportional hazards model with a time-varying covariate for CMV shedding, the partial likelihood depends on the covariate status of every individual in the risk set at each failure time. Due to interval censoring, this is not always known. To solve this problem, we use a Monte Carlo EM algorithm with a Gibbs sampler embedded in the E-step. We generate multiple completed data sets by drawing imputed exact shedding times based on the joint likelihood of the shedding times and event times under the Cox model. The method is evaluated using a simulation study and is applied to the data set described above.

A Phase I study of continuous infusion doxorubicin and paclitaxel chemotherapy with granulocyte colony-stimulating factor for relapsed epithelial ovarian cancer

A Phase I study of paclitaxel and doxorubicin administered as concurrent 96-h continuous i.v. infusion was performed to determine the maximum tolerated dose (MTD), principal toxicities, and pharmacokinetics of this combination in women with relapsed epithelial ovarian cancer. The paclitaxel dose was fixed at 100 mg/m2 (25 mg/m2/day for 4 days). The dose of doxorubicin was escalated from 30 mg/m2 (7.5 mg/m2/day for 4 days) in increments of 10 mg/m2 until dose-limiting toxicity was observed. All patients received granulocyte colony-stimulating factor 5 microg/kg/day prophylactically. Apparent steady-state plasma levels of both drugs were determined in the final cohort of patients treated at the MTD. A total of 17 patients received 52 cycles of therapy. The median age was 58 years, and all patients had previously received one to five different regimens (median, 2) of chemotherapy, including both platinum and paclitaxel. The treatment was tolerated well, with grade 1-2 nausea being the most frequent side effect (73% of cycles). Anemia, neutropenia, thrombocytopenia, and mucositis became dose limiting at the fourth dose level, defining the MTD of doxorubicin in this regimen as 50 mg/m2. There were four partial responses and one complete response in 15 evaluable patients. Apparent steady-state plasma concentrations (mean +/- SD) of paclitaxel and doxorubicin in the three patients treated at the MTD were 33.9 +/- 12.5 nM and 15.7 +/- 1.3 nM, respectively. Paclitaxel and doxorubicin by continuous infusion is a well-tolerated and active chemotherapy regimen for recurrent ovarian cancer.

Prognosis and survival in patients with gastrointestinal tract carcinoid tumors

OBJECTIVE

To determine the impact of clinical presentation variables on the management and survival of patients with gastrointestinal (GI) tract carcinoid tumors.

METHODS

A 20-year (1975-1995) retrospective analysis of 150 patients with GI tract carcinoid tumors at the Massachusetts General Hospital was conducted. Median follow-up was 66 months (range 1-378). Survival estimates for prognostic factors were calculated using Kaplan-Meier product limit estimators, with death from carcinoid as the outcome. Univariate analyses for each factor were obtained using a log-rank test, and multivariate survival analysis was performed.

RESULTS

All but two patients underwent surgical intervention with the intent to cure (90%) or debulk the tumor (9%). Mean age at presentation was 55 +/- 18 years (range 11-90). There was a slight female/male predominance (80:70). Symptoms were nonspecific; the most common were abdominal pain (40%), nausea and vomiting (29%), weight loss (19%), and GI blood loss (15%). Incidental carcinoids, discovered at the time of another procedure, occurred in 40% of patients and were noted at multiple sites throughout the GI tract. The distribution of tumors was ileojejunum (37%), appendix (31 %), colon (13%), rectum (12%), stomach (4%), duodenum (1.3%), and Meckel's diverticulum (1.3%). Of the 27 patients with documented liver metastases, carcinoid syndrome developed in only 13 patients (48%), manifested by watery diarrhea (100%), upper body flushing (70%), asthma (38%), and tricuspid regurgitation (23%). All 13 patients with carcinoid syndrome had elevated levels of 5-HIAA, but the absolute levels did not correlate with the severity of symptoms. An additional 11 patients, 3 without liver metastases, had elevated levels of 5-HIAA without any evidence of carcinoid syndrome. Multicentric carcinoid tumors occurred in 15 patients (10%), and all but one of these tumors were centered around the ileocecal valve. There was no difference in the incidence of liver metastases between solitary (18%) and multicentric carcinoids (20%). Synchronous noncarcinoid tumors were present in 33 patients (22%), and metachronous tumors developed in an additional 14 patients (10%) in follow-up. Age and tumor size, depth, and location were significant predictors of metastases. By multivariate analysis, age > or = 50 years, metastases, and male gender were statistically significant predictors of death.

CONCLUSIONS

Gastrointestinal tract carcinoid tumors have a nonspecific clinical presentation, except in the case of the carcinoid syndrome. Surgical resection is the treatment of choice for improving survival. Surgically treated patients with carcinoid tumor have an overall favorable 83% 5-year survival rate.

Multimodality management of Merkel cell carcinoma

HYPOTHESIS

Merkel cell carcinoma is a rare dermal neuroendocrine carcinoma whose optimal treatment and prognostic factors are poorly defined. We hypothesize that high-risk patients with Merkel cell carcinoma are best treated with multimodality therapy.

DESIGN

A retrospective review of all patients (N = 33) with Merkel cell carcinoma treated at the Massachusetts General Hospital from January 1, 1980, to August 24,1997. Median follow-up time was 37 months (range, 6-157 months).

PATIENTS

Adequate data for evaluation were available for 31 patients. Male to female distribution was 14 men and 17 women, with a median patient age of 68 years.

MAIN OUTCOME MEASURE

Stage at presentation; factors associated with recurrence; and the effects of surgery, radiation therapy (XRT), and chemotherapy on recurrence, salvage, and survival rates.

RESULTS

There were 12 extremity, 11 head and neck, and 8 truncal tumors. There were 22 isolated primary tumors, 8 with additional clinically positive lymph nodes, and 1 with distant disease. Therapy was local excision with or without XRT in 19 patients, local resection and lymphadenectomy with or without XRT in 8 patients, and XRT alone in 4 patients with head and neck tumors. Fifteen patients developed recurrences (7 local, 8 nodal, and 10 distant). Median time to recurrence was 8 months (range, 3-48 months). There were 7 tumor-related deaths, 6 of which were associated with truncal lesions (P<.001). No locoregional recurrences occurred in patients with margins of resection of 2 cm or greater or adequate XRT. A multivariate analysis selected truncal location (P = .005) and nodal disease (P = .05) as predictors of mortality. Remission was possible in 5 patients with locoregional and 2 patients with distant recurrences.

CONCLUSIONS

Merkel cell carcinoma is an aggressive dermal cancer with frequent nodal metastases; truncal tumors have the worst prognosis. Locoregional recurrence correlates with inadequate margins and lack of XRT, but remission is possible with multimodality therapy.

A Markov chain Monte Carlo EM algorithm for analyzing interval-censored data under the Cox proportional hazards model

This paper proposes a Monte Carlo EM (MCEM) algorithm for fitting the proportional hazards model for interval-censored failure-time data. The algorithm generates orderings of the failures from their probability distribution under the model. We maximize the average of the log-likelihoods from these completed data sets to obtain updated parameter estimates. As with the standard Cox model, this algorithm does not require the estimation of the baseline hazard function. The performance of the algorithm is evaluated using simulations, and the method is applied to data from AIDS and cancer studies. Our results indicate that our method produced more precise and unbiased estimates than methods of right and midpoint imputation.

Specific genetic predictors of chemotherapeutic response and survival in patients with anaplastic oligodendrogliomas

BACKGROUND/METHODS

Gliomas are common malignant neoplasms of the central nervous system. Among the major subtypes of gliomas, oligodendrogliomas are distinguished by their remarkable sensitivity to chemotherapy, with approximately two thirds of anaplastic (malignant) oligodendrogliomas responding dramatically to combination treatment with procarbazine, lomustine, and vincristine (termed PCV). Unfortunately, no clinical or pathologic feature of these tumors allows accurate prediction of their response to chemotherapy. Anaplastic oligodendrogliomas also are distinguished by a unique constellation of molecular genetic alterations, including coincident loss of chromosomal arms 1p and 19q in 50%-70% of tumors. We have hypothesized that these or other specific genetic changes might predict the response to chemotherapy and prognosis in patients with anaplastic oligodendrogliomas. Therefore, we have analyzed molecular genetic alterations involving chromosomes 1p, 10q, and 19q and the TP53 (on chromosome 17p) and CDKN2A (on chromosome 9p) genes, in addition to clinicopathologic features in 39 patients with anaplastic oligodendrogliomas for whom chemotherapeutic response and survival could be assessed.

RESULTS/CONCLUSIONS

Allelic loss (or loss of heterozygosity) of chromosome 1p is a statistically significant predictor of chemosensitivity, and combined loss involving chromosomes 1p and 19q is statistically significantly associated with both chemosensitivity and longer recurrence-free survival after chemotherapy. Moreover, in both univariate and multivariate analyses, losses involving both chromosomes 1p and 19q were strongly associated with longer overall survival, whereas CDKN2A gene deletions and ring enhancement (i.e., contrast enhancement forming a rim around the tumor) on neuroimaging were associated with a significantly worse prognosis. The inverse relationship between CDKN2A gene deletions and losses of chromosomes 1p and 19q further implies that these differential clinical behaviors reflect two independent genetic subtypes of anaplastic oligodendroglioma. These results suggest that molecular genetic analysis may aid therapeutic decisions and predict outcome in patients with anaplastic oligodendrogliomas.

Early vs delayed administration of G-CSF following autologous peripheral blood stem cell transplantation

It is well established that recombinant human G-CSF accelerates neutrophil recovery following autologous peripheral blood stem cell transplantation (PBSCT). However, the optimal timing of G-CSF following transplantation remains unknown. We have conducted a retrospective analysis of patients treated with either early, day +1 (n = 42) or delayed, day +4 (n = 39) administration of G-CSF following autologous PBSCT for a variety of hematologic malignancies and solid tumors. G-CSF was given at a dose of 5 microg/kg/day i.v. as a 2 h infusion beginning either day +1 or day +4 following PBSC infusion and continued until the total white blood count (WBC) was >10 x 10(9)/l. The numbers of transplanted CD34+ cells were similar in each group. Treatment with early administration of G-CSF resulted in a significantly shorter time to an absolute neutrophil count (ANC) of >0.5 x 10(9)/l (8.5 vs 10.0 days, P < 0.0003) and shorter length of hospitalization (16.3 vs 18.6 days, P < 0.0008), a trend towards a reduced incidence of infection (53 vs 72%) and a significant decrease in the duration of non-prophylactic antibiotic (NPA) therapy for neutropenic fever (4.0 vs 7.5 days, P < 0.009) compared to day +4 administration. Despite the additional cost of G-CSF, the reduction in the hospitalization and NPA therapy with early G-CSF administration resulted in 11% cost savings overall per transplant at our institution.

Temporal lobe (TL) damage following surgery and high-dose photon and proton irradiation in 96 patients affected by chordomas and chondrosarcomas of the base of the skull

PURPOSE

To determine the temporal lobe (TL) damage rate in 96 patients treated with high-dose proton and photon irradiation for chordomas and chondrosarcomas of the base of the skull.

METHODS AND MATERIALS

The records of 96 consecutive patients treated at Massachusetts General Hospital (MGH) and Harvard Cyclotron Laboratory (HCL) between June 1984 and 1993, for chordomas and chondrosarcomas of the base of the skull were reviewed. All the patients had undergone some degree of resection of the tumor prior to radiation therapy. Seventy-five patients were classified as "primary tumors" and 21 as recurrent or regrowing tumors after one or more surgical procedures. All the patients were randomized to receive 66.6 or 72 cobalt Gray equivalent (CGE) on a prospective dose-searching study by proton and photon irradiation (Radiation Therapy Oncology Group #85-26) with conventional fractionation (1.8 CGE/day, 5 fractions/week). All treatments were planned using the three-dimensional (3D) planning system developed at the Massachusetts General Hospital, and the dose was delivered using opposed lateral fields for the photon component and a noncoplanar isocentric technique for the proton component. Clinical symptoms of TL damage were classified into 4 grades. Computerized tomography (CT) and magnetic resonance imaging (MRI) scans were evaluated for white matter changes. Abnormalities associated with persistent or recurrent tumor were distinguished from radiation-induced changes. TLs were delineated on the original scans of the 10 patients with damage and those of a group of 33 patients with no clinical or MRI evidence of injury. Dose distributions were calculated and dose-volume histograms were obtained for these patients.

RESULTS

Of the patients, 10 developed TL damage, with bilateral injury in 2 and unilateral injury in 8. The cumulative TL damage incidence at 2 and 5 years was 7.6 and 13.2%, respectively. The MRI areas suggestive of TL damage were always separated from the tumor bed. Symptoms were severe to moderate in 8 patients. Several baseline factors, tumor- or host-related, were analyzed to evaluate their predictivity for TL damage: age, gender, tumor site, histology, type of presentation, type and number of surgical procedures, primary tumor volume, prescribed dose, normal tissue involvement, and volume of TL receiving doses ranging between 10 and 50 CGE or more. Only gender, in a univariate analysis (log rank) was a significant predictor of damage (0.0155), with male patients being at significantly higher risk of TL injury. In a stepwise Cox regression that included gender as a variable, no other baseline variable improved the prediction of damage.

CONCLUSIONS

The 2- and 5-year cumulative TL damage rates were 7.6 and 13.2%, respectively. Despite the different TL damage rates related to age, tumor volume, number of surgical procedures prior to radiation therapy, and prescribed doses to the tumor, only gender was a significant predictor of damage (p = 0.0155) using a univariate (log rank) test. Chordomas and chondrosarcomas of the base of the skull may represent an interesting model to evaluate the TL damage rates because of their extradural origin, displacing the white matter instead of infiltrating it as gliomas do, because of their longer local recurrence-free survival other than gliomas and other brain tumors and because of the high doses of irradiation delivered to the target volume to obtain local control.

Decreased serotonin function in bulimia nervosa

BACKGROUND

Evidence that serotonin-active antidepressant medications decrease binge eating in patients with bulimia nervosa has fueled interest in the hypothesis that abnormal serotonergic neurotransmitter function contributes to symptoms of the disorder. To evaluate this hypothesis, we employed pharmacological challenge testing to compare serotonin function in patients with bulimia nervosa and healthy controls.

METHODS

Neuroendocrine response patterns were compared for 15 nonhospitalized, medication-free, normal-weight women with bulimia nervosa and 14 age-matched healthy female controls. Behavioral assessment included ratings of eating disorder symptoms, depression, and anxiety. Serotonergic response patterns were assessed by measuring the increase in serum prolactin concentration during 5 hours following single-dose, oral administration of 60 mg of d,l-fenfluramine hydrochloride (Pondimin).

RESULTS

For patients with bulimia nervosa, the fenfluramine-stimulated increase in serum prolactin concentration was significantly less than for controls. Within the patient group, the frequency of binge eating episodes during the 4 weeks prior to the study exhibited a significant inverse correlation with serotonin-stimulated prolactin secretion.

CONCLUSION

Our study provides new evidence that impaired central nervous system serotonergic responsiveness may contribute to the onset or maintenance of abnormal eating patterns in patients with bulimia nervosa.

Differential contributions of BRCA1 and BRCA2 to early-onset breast cancer

BACKGROUND

Germ-line mutations in the BRCA1 and BRCA2 genes predispose women to breast cancer. BRCA1 mutations are found in approximately 12 percent of women with breast cancer of early onset, and the specific mutation causing a deletion of adenine and guanine (185delAG), which is present in 1 percent of the Ashkenazi Jewish population, contributes to 21 percent of breast cancers among young Jewish women. The contribution of BRCA2 mutations to breast cancer of early onset is unknown.

METHODS

Lymphocyte specimens from 73 women with breast cancer diagnosed by the age of 32 were studied for heterozygous mutations of BRCA2 by a complementary-DNA-based protein-truncation assay, followed by automated nucleotide sequencing. In addition, specimens from 39 Jewish women with breast cancer diagnosed by the age of 40 were tested for specific mutations by an allele-specific polymerase chain reaction.

RESULTS

Definite BRCA2 mutations were found in 2 of the 73 women with early-onset breast cancer (2.7 percent; 95 percent confidence interval, 0.4 to 9.6 percent), suggesting that BRCA2 is associated with fewer cases than BRCA1 (P=0.03). The specific BRCA2 mutation causing a deletion of thymine (6174delT), which is found in 1.3 percent of the Ashkenazi Jewish population, was observed in 1 of the 39 young Jewish women with breast cancer (2.6 percent; 95 percent confidence interval, 0.09 to 13.5 percent), indicating that it has a small role as a risk factor for early-onset breast cancer. Among young women with breast cancer, there are BRCA2 mutations that cause truncation of the extreme C terminus of the protein and that may be functionally silent, along with definite truncating mutations.

CONCLUSIONS

Germ-line mutations in BRCA2 contribute to fewer cases of breast cancer among young women than do mutations in BRCA1. Carriers of BRCA2 mutations may have a smaller increase in the risk of early-onset breast cancer.

Analysis of multiple failure time data from an AIDS clinical trial

The primary endpoint of AIDS prophylaxis trials is the occurrence of opportunistic infections. While the treatments are not expected to have an effect on the underlying HIV disease, an effect of treatments on mortality cannot be ruled out. Therefore, the primary analysis of these trials must be based on a combined endpoint of infection and survival times. There are several methods available for analysis of multiple failure time data. However, there is no standard method for combining mortality and other failures in these analyses. This paper explores the analysis of multiple infections in the context of a study in which treatments may have an effect on mortality. The methods are applied to an AIDS clinical trial of prophylaxis for fungal infections.

High risk of breast carcinoma after irradiation of young women with Hodgkin's disease

BACKGROUND

Treatment-associated second neoplasms have emerged as a major threat to the continued survival of patients cured of Hodgkin's disease. In this study, the authors investigated the risk of breast carcinoma in an irradiated Hodgkin's disease population.

METHODS

One hundred and eleven women younger than 60 years presenting between 1964 and 1984 with Stage I and II Hodgkin's disease who received mantle irradiation were retrospectively analyzed and compared with an age specific population. Median follow-up was 18 years (range, 10-30 years), and the median age at initiation of therapy was 24 years. Kaplan-Meier actuarial risks, relative risks (RRs) (the ratio of the observed to the expected cases) with 95% confidence intervals (CIs), and the log rank test for trends were calculated.

RESULTS

Fourteen women developed breast carcinoma: 8 of 33 patients younger than 20 years at the time of irradiation, 5 of 48 patients age 20 to 29 years, and 1 of 30 patients age 30 years or older. Actuarial calculation predicted a 34.0% (CI, 14.2-53.8) risk of breast carcinoma at 25 years after therapy for the youngest group, 22.3% (CI, 4.1-40.5) for the group of intermediate age, and 3.5% (CI, 0-10.1) for the oldest group. The RR of breast carcinoma was 56 (CI, 23.3-107) for those 19 years or younger at the time of treatment, 7.0 (CI, 2.3-16.4) for those age 20-29 years, and 0.9 (CI, 0-5.3) for those 30 years and older. Excluding 1 patient who was age 38 years at the time of irradiation, the remaining 13 breast carcinomas were tightly clustered in women irradiated between the ages of 14 through 25, and were detected in years 11 through 25 after treatment, with 7 occurring in years 15 through 18.

CONCLUSIONS

Women younger than 30 years, particularly those younger than 20 years, who have received mantle irradiation for Hodgkin's disease require meticulous follow-up for breast carcinoma. The high incidence of breast carcinoma in this patient population should be considered when making treatment decisions in young women with early stage Hodgkin's disease.

Heterozygous ATM mutations do not contribute to early onset of breast cancer

Ataxia telangiectasia (AT) is a recessive syndrome, including cerebellar degeneration, immunologic defects and cancer predisposition, attributed to mutations in the recently isolated ATM (ataxia telangiectasia, mutated) gene. AT is diagnosed in 1/40,000 to 1/100,000 live births, with carriers calculated to comprise approximately 1% of the population. Studies of AT families have suggested that female relatives presumed to be carriers have a 5 to 8-fold increased risk for developing breast cancer, raising the possibility that germline ATM mutations may account for approximately 5% of all breast cancer cases. The increased risk for breast cancer reported for AT family members has been most evident among younger women, leading to an age-specific relative risk model predicting that 8% of breast cancer in women under age 40 arises in AT carriers, compared with 2% of cases between 40-59 years. To test this hypothesis, we undertook a germ-line mutational analysis of the ATM gene in a population of women with early onset of breast cancer, using a protein truncation (PTT) assay to detect chain-terminating mutations, which account for 90% of mutations identified in children with AT. We detected a heterozygous ATM mutation in 2/202 (1%) controls, consistent with the frequency of AT carriers predicted from epidemiologic studies. ATM mutations were present in only 2/401 (0.5%) women with early onset of breast cancer (P = 0.6). We conclude that heterozygous ATM mutations do not confer genetic predisposition to early onset of breast cancer.

Prevalence of germ-line mutations in p16, p19ARF, and CDK4 in familial melanoma: analysis of a clinic-based population

Five to ten percent of individuals with melanoma have another affected family member, suggesting familial predisposition. Germ-line mutations in the cyclin-dependent kinase (CDK) inhibitor p16 have been reported in a subset of melanoma pedigrees, but their prevalence is unknown in more common cases of familial melanoma that do not involve large families with multiple affected members. We screened for germ-line mutations in p16 and in two other candidate melanoma genes, p19ARF and CDK4, in 33 consecutive patients treated for melanoma; these patients had at least one affected first or second degree relative (28 independent families). Five independent, definitive p16 mutations were detected (18%, 95% confidence interval: 6%, 37%), including one nonsense, one disease-associated missense, and three small deletions. No mutations were detected in CDK4. Disease-associated mutations in p19ARF, whose transcript is derived in part from an alternative codon reading frame of p16, were only detected in patients who also had mutations inactivating p16. We conclude that germ-line p16 mutations are present in a significant fraction of individuals who have melanoma and a positive family history.

Patterns of opportunistic infections in patients with HIV infection

The pattern of the development of opportunistic infections (OIs) in HIV-infected patients was evaluated, based on a cohort of 1,530 patients enrolled in two AIDS Clinical Trials Group anti-retroviral studies. We quantified the increase in risk of OIs associated with the occurrence of a previous OI. This assessment was based on the observed event rates of the more common AIDS-defining OIs: Pneumocystis carinii pneumonia (PCP), Mycobacterium avium complex (MAC), cytomegalovirus (CMV), and a systemic mycosis. Additionally, for each OI, we assessed the relative risks associated with a history of prior OIs, changes in CD4 levels, and baseline prognostic factors. We found that the occurrence of each of these OIs increased the risk of subsequent OIs, even after adjusting for the CD4 count. Specifically, the occurrence of PCP significantly increased the risk of MAC and CMV, and somewhat increased the risk of systemic mycoses. Diagnosis with MAC was associated with an increased risk of subsequent CMV, whereas the occurrence of CMV increased the risk of MAC. Finally, once patients were diagnosed with a systemic mycosis, they were at a somewhat increased risk of subsequently developing MAC or CMV. Although current practice for determining the timing and initiation of prophylactic therapies relies chiefly on CD4 count, the occurrence of specific AIDS-defining OIs in patients with HIV infection should also be taken into account in making decisions regarding prophylaxis strategies.

Comparison of three regimens for treatment of mild to moderate Pneumocystis carinii pneumonia in patients with AIDS. A double-blind, randomized, trial of oral trimethoprim-sulfamethoxazole, dapsone-trimethoprim, and clindamycin-primaquine. ACTG 108 Study Group

OBJECTIVE

To compare the tolerability and efficacy of three oral regimens for the treatment of patients with the acquired immunodeficiency syndrome (AIDS) and Pneumocystis carinii pneumonia.

DESIGN

A randomized, double-blind study.

SETTING

24 U.S. academic medical centers.

PATIENTS

181 patients with morphologically confirmed P. carinii pneumonia and alveolar-arterial oxygen differences (PAO2-PaO2) of 45 mm Hg or less.

INTERVENTION

Patients were randomly assigned to receive trimethoprim-sulfamethoxazole, dapsone-trimethoprim, or clindamycin-primaquine for 21 days. Patients with a PAO2-PaO2 of 35 to 45 mm Hg at study entry also received prednisone.

MEASUREMENTS

Serial clinical and laboratory evaluations for therapeutic response and toxicity. Therapeutic failure at day 21 was defined by any of the following: increase in PAO2-PaO2 of greater than 20 mm Hg; no remission of baseline signs and symptoms; and change in antipneumocystis therapy for reasons other than toxicity, intubation, or death. Dose-limiting toxicity was defined as discontinuation of therapy by the primary physician because of one or more adverse reactions.

RESULTS

No statistically significant differences were seen among treatment groups in the proportions of patients who had dose-limiting toxicity (P=0.2), therapeutic failure (P>0.2), or a complete course of therapy (P>0.2). Survival during therapy or for 2 months thereafter did not differ among the three groups (P>.02). However, elevation of serum aminotransferase levels to more than five times the baseline levels was more frequent in the trimethoprim-sulfamethoxazole group (P=0.003), and one or more serious hematologic toxicities (neutropenia, anemia, thrombocytopenia, or methemoglobinemia) occurred more frequently in the clindamycin-primaquine group (P=0.01).

CONCLUSIONS

The rates of dose-limiting toxicity, therapeutic failure, and survival did not differ among patients with AIDS who were receiving oral trimethoprim-sulfamethoxazole, dapsone-trimethoprim, or clindamycin-primaquine for mild to moderate P. carinii pneumonia. However, the limited sample size prevents the unequivocal demonstration of the equality of these three regimens. Differences in expected categories of toxicities associated with each regimen should guide the clinician in choosing first-line therapy, particularly for patients with baseline hepatic insufficiency or myelosuppression.

A phase II study of recombinant human interferon-alpha 2a and zidovudine in patients with AIDS-related Kaposi's sarcoma. AIDS Clinical Trials Group

To assess safety, antitumor response, and immunological and virological activity of interferon-alpha 2a and zidovudine combination therapy in patients with AIDS-related Kaposi's sarcoma, we conducted an open-label, Phase II, multicenter study. Sixty-three patients with biopsy-proven Kaposi's sarcoma and no previous interferon-alpha therapy received zidovudine 600 mg/day and interferon-alpha 2a 18 x 10(6) U/day. The median duration of follow-up was 49 weeks. Of 62 evaluable patients, 25 (40%; 95% confidence interval, 0.28-0.52) showed a complete (26%) or partial (15%) antitumor response. Eight of 30 patients (27%) with < 100 CD4 cells/mm3 and 17 of 32 patients (53%) with > or = 100 CD4 cells/mm3 had a response. The median time to response was 36 weeks. Of the 25 patients with a response, four developed tumor progression. The median duration of response was 22.4 weeks. Eight patients (13%) developed another AIDS-defining event and 13 (21%) died. The major toxicities included anemia (16%), neutropenia (27%), elevated serum transaminases (16%), weight loss (16%), malaise (14%), fatigue (14%), fever (10%), and headache (6%). Therapy with intermediate-dose interferon-alpha 2a and zidovudine resulted in tumor regression in patients with AIDS-related Kaposi's sarcoma who had a wide range of CD4 cell counts; this therapy was relatively well tolerated.

Germ-line BRCA1 mutations in Jewish and non-Jewish women with early-onset breast cancer

BACKGROUND

Mutations in a germ-line allele of the BRCA1 gene contribute to the familial breast cancer syndrome. However, the prevalence of these mutations is unknown in women with breast cancer who do not have the features of this familial syndrome. We sought BRCA1 mutations in women who were given a diagnosis of breast cancer at an early age, because early onset is characteristic of a genetic predisposition to cancer.

METHODS

Clinical information and peripheral-blood mononuclear cells were obtained from 418 women from the Boston metropolitan area in whom breast cancer was diagnosed at or before the age of 40. A comprehensive BRCA1 mutational analysis, involving automated nucleotide sequencing and a protein-truncation assay, was undertaken in 30 of these women, who had breast cancer before the age of 30. In addition, the BRCA1 mutation 185delAG, which is prevalent in the Ashkenazi Jewish population, was sought with an allele-specific polymerase-chain-reaction assay in 39 Jewish women among the 418 women who had breast cancer at or before the age of 40.

RESULTS

Among 30 women with breast cancer before the age of 30, 4 (13 percent) had definite, chain-terminating mutations and 1 had a missense mutation. Two of the four Jewish women in this cohort had the 185delAG mutation. Among the 39 Jewish women with breast cancer at or before the age of 40, 8 (21 percent) carried the 185delAG mutation (95 percent confidence interval, 9 to 36 percent).

CONCLUSIONS

Germ-line BRCA1 mutations can be present in young women with breast cancer who do not belong to families with multiple affected members. The specific BRCA1 mutation known as 185delAG is strongly associated with the onset of breast cancer in Jewish women before the age of 40.

Phase II study of paclitaxel in patients with extensive-disease small-cell lung cancer: an Eastern Cooperative Oncology Group study

PURPOSE

To evaluate the efficacy and safety of paclitaxel (Taxol; Bristol-Myers Squibb Co, Princeton, NJ), a novel diterpene plant product in the treatment of previously untreated patients with extensive-disease small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Patients with extensive-disease SCLC received paclitaxel 250 mg/m2 intravenously over 24 hours every 3 weeks. Nonresponders or partial responders, who received the maximum number of cycles (n = 4) of paclitaxel received salvage chemotherapy that consisted of etoposide (VP-16) 120 mg/m2 intravenously over 45 minutes on days 1, 2, and 3, and cisplatin 60 mg/m2 intravenously as a short infusion on day 1. Cycles were repeated every 3 weeks.

RESULTS

Of 36 patients entered onto the study, 34 and 32 patients were assessable for toxicity and response, respectively. No complete responses (CRs) were observed. Eleven patients (34%) had a partial response (PR) and six (19%) had stable disease (SD). In three of six patients categorized as having SD, there was greater than 50% tumor shrinkage. However, no 4-week follow-up measurements were made, so these could not be considered PRs, in part because patients received salvage chemotherapy by study design. In this trial, induction and salvage chemotherapy resulted in a response (two CRs and 15 PRs) (53%) in 17 patients. The estimated median survival duration was 43 weeks. Dose-limiting toxicity was leukopenia, with 19 patients (56%) having grade 4 leukopenia. The numbers of patients who experienced other grade 4 toxicities were as follows: pulmonary, three (9%); liver, two (6%); cardiac, one (3%); thrombocytopenia, one (3%); metabolic, one (3%); stomatitis, one (3%); and allergic reaction, one (3%). Four additional patients had grade 3 leukopenia and one patient (3%) died of sepsis (grade 5 toxicity).

CONCLUSION

Paclitaxel is an active new agent in the treatment of SCLC. Further investigation of this agent in combination with other active agents is appropriate.

A randomized trial of three antipneumocystis agents in patients with advanced human immunodeficiency virus infection. NIAID AIDS Clinical Trials Group

BACKGROUND

We evaluated the effectiveness of three treatment strategies for the prevention of a first episode of Pneumocystis carinii pneumonia in patients infected with the human immunodeficiency virus (HIV).

METHODS

In an open-label trial, 843 patients with HIV infection and fewer than 200 CD4+ cells per cubic millimeter received zidovudine plus one of three randomly assigned prophylactic agents, beginning with trimethoprim-sulfamethoxazole, dapsone, or aerosolized pentamidine and followed by a defined sequence of other drugs to be used in cases of intolerance.

RESULTS

The estimated 36-month cumulative risks of P. carinii pneumonia were 18 percent, 17 percent, and 21 percent in the trimethoprim-sulfamethoxazole, dapsone, and aerosolized-pentamidine groups, respectively (P = 0.22). The difference in risk among treatment strategies was negligible in patients entering the study with 100 or more CD4+ lymphocytes per cubic millimeter. In those entering with fewer than 100 CD4+ cells per cubic millimeter, the risk was 33 percent with aerosolized pentamidine, as compared with 19 percent with trimethoprim-sulfamethoxazole and 22 percent with dapsone (P = 0.04). The lowest failure rates occurred in patients receiving trimethoprim-sulfamethoxazole, and failures were more common with 50 mg of dapsone than with 100 mg. Toxoplasmosis developed in less than 3 percent of patients. Of the patients assigned to the two systemic therapies, only 23 percent were receiving their assigned drug and dose when they completed the study. The median survival was approximately 39 months in all three groups, and the mortality attributable to P. carinii pneumonia was only 1 percent.

CONCLUSIONS

In patients with advanced HIV infection, the three treatment strategies we examined have similar effectiveness in preventing P. carinii pneumonia. Strategies that start with trimethoprim-sulfamethoxazole or with high-dose dapsone, rather than aerosolized pentamidine, are superior in patients with fewer than 100 CD4+ lymphocytes per cubic millimeter.

Cognitive function in patients with insulin-dependent diabetes mellitus during hyperglycemia and hypoglycemia

BACKGROUND

To determine the impact of glycemic control, gender, and other relevant parameters on cognitive function during exposure to different blood glucose levels in patients with insulin-dependent diabetes mellitus (IDDM), we examined neuropsychologic function during experimentally induced periods of hyperglycemia and hypoglycemia.

METHODS

We studied 20 men and 22 women, aged 18 to 44 years, with IDDM duration of 3 to 14 years and HbA1 values ranging from 5.8% to 18.0% (nondiabetic range 5.4% to 7.4%). We used a controlled experimental setting involving tests of sensory perceptual processing, simple motor abilities, attention, learning and memory, language, and spatial and constructional abilities at plasma glucose levels of 2.2, 5.6, 8.9, 14.4, and 21.1 mmol/L. Patients were blind to the glucose level. Tests used at each glucose level included reaction time (simple and choice), digit vigilance, trail making part B, word recall, digit sequence learning, and verbal fluency.

RESULTS

All aspects of neuropsychologic function were diminished at 2.2 mmol/L when compared with basal levels of performance at 8.9 mmol/L, whereas no alterations were observed at 14.4 or 21.1 mmol/L. Tests involving associative learning, attention, and mental flexibility were the most affected during hypoglycemia. Glycemic control was not correlated with neuropsychologic function at any glucose level. Women demonstrated less of an impairment in neuropsychologic function than men at 2.2 mmol/L.

CONCLUSIONS

Cognitive function in IDDM patients was generally well-preserved even at substantially elevated blood glucose levels. Deficits in all relevant areas of cognitive function occurred during hypoglycemia (2.2 mmol/L), irrespective of prior glycemic control, and women with IDDM were less cognitively impaired than men with IDDM during hypoglycemia.

Blood glucose estimation and symptoms during hyperglycemia and hypoglycemia in patients with insulin-dependent diabetes mellitus

PURPOSE

To investigate hypoglycemic and hyperglycemic symptoms, accuracy of estimating blood glucose, and their relation to glycemic control and counterregulatory hormone levels in insulin-dependent diabetes mellitus.

PATIENTS AND METHODS

During randomly ordered stepped hypoglycemic and hyperglycemic insulin clamps on two separate days, 42 patients with insulin-dependent diabetes mellitus rated the intensity of 40 moods and symptoms when glucose was 8.9, 5.6 and 2.2 mmol/L, and 8.9, 14.4 and 21.1 mmol/L. The subjects were blinded to their actual glucose levels and asked to estimate them at each step. Epinephrine, norepinephrine, cortisol, growth hormone, and glucagon were measured at each glucose plateau.

RESULTS

Cluster analysis yielded five symptom groups during hypoglycemia: autonomic symptoms, negative moods, positive moods, feeling weak/dizzy, and feeling relaxed. At 2.2 mmol/L, mean scores for all five symptom groups and 11 of 17 unclustered symptoms differed from those reported at the baseline glucose of 8.9 mmol/L (P < or = 0.05), but 34% of patients reported no awareness of autonomic symptoms. The intensity of autonomic symptoms correlated positively with HbA1 (r = .43, P < 0.01), epinephrine (r = .59, P < 0.001), norepinephrine (r = .45, P < 0.01) and cortisol (r = .62, P < 0.001), and negatively with glucose estimation error (r = -.45, P = 0.01). Six patients (15%) were unaware of both autonomic and neuroglycopenic symptoms during hypoglycemia. At 21.1 mmol/L, only 5 of 40 symptoms differed (P < 0.05) from baseline. Seventeen percent of subjects made potentially serious errors when estimating glucose at 2.2 mmol/L, and 66% at 21.1 mmol/L. Many patients experienced symptoms different from those they reported as their usual manifestations of changing glucose levels.

CONCLUSIONS

Since the majority of patients made clinically serious errors in glucose estimation, and many used symptoms that did not discriminate hyperglycemia and hypoglycemia, individualized training to increase awareness of glucose-related symptoms and glucose levels may help patients reduce the frequency or severity of hyperglycemic and hypoglycemic events.

Analysing survival in the presence of an auxiliary variable

A primary endpoint of AIDS trials is the length of survival. Often there is auxiliary information available on measures of disease progression, which significantly alter the risk of mortality. This paper explores the use of this information in obtaining a refined estimate of survival, and a test based on this estimate. The methods are applied to an AIDS clinical trial, and results of simulations are provided which compare the approach to standard methods for survival analysis.

Computer interview for screening blood donors for risk of HIV transmission

To test the ability of a computer-based interview to detect factors related to the risk of the human immunodeficiency virus (HIV) among potential blood donors, and to determine donor reactions to the use of the computer, we compared the rate of detection of HIV-related factors elicited by the computer interview with the rate elicited by standard American Red Cross procedures (written questionnaires and face-to-face interviews) for assessment of donor suitability. The study was performed at a Red Cross blood donor center and a hospital. A consecutive sample of 294 male and female blood donors 18 to 75 years of age participated in a randomized crossover trial in which the order of the two methods was reversed. Among 272 prospective donors who provided complete data, the computer identified 12 who reported either behavior associated with a risk of acquiring HIV or symptoms compatible with AIDS. None of these 12 was so identified by face-to-face interviews or written questionnaires. Only one used the confidential unit exclusion procedure to prevent use of his donated blood. Tests for antibody to HIV were negative in blood from all 272 subjects. The subjects enjoyed the computer interview and judged it to be more private than the standard method for donor assessment.

Determinants of accrual of women to a large, multicenter clinical trials program of human immunodeficiency virus infection. The AIDS Clinical Trials Group

To determine factors influencing the enrollment of women in a large multicenter human immunodeficiency virus (HIV) clinical trials program in the United States, we analyzed enrollment and demographic data of the AIDS Clinical Trials Group (ACTG) during the period 1987-90. Women comprised 6.7% of 11,909 ACTG participants enrolled in 1987-90. Women entering ACTG trials were significantly more likely to be white (48.5%) and less likely to have ever used i.v. drugs (22.6%) than U.S. women reported to have AIDS (26.5% were white; 51.0% had ever used i.v. drugs, p < 0.0001). In a multiple logistic regression model, specific attributes of individual trials did not influence enrollment of women with the exception that trials that targeted asymptomatic persons had greater enrollment of women. There was wide variation among research units in the percentage of women enrolled (1.0-37.5%), and evidence of significant regional variation in the ability of units to recruit available women. Units with female principal or coprincipal investigators had more than twice the percentage of female enrollment as units headed by men (10.8 vs. 5.3%, p < 0.001). Enrollment of women in a large HIV clinical trials program was low and appeared to be influenced more by demographic and geographic factors that attributes of specific trials. An apparent positive influence of female leadership on the enrollment of women warrants further study.

A proportional hazards model for truncated AIDS data

An important source of information on the latency period for AIDS is the data from individuals infected by contaminated blood transfusion. However, a difficulty in the analysis and interpretation of these data is that information is available only on individuals who are infected and develop the disease prior to some specific time. In this paper, we propose an approach to the analysis of such data under a proportional hazards model. The proposed approach allows testing for group effects in the presence of multiple explanatory variables.

Influence of implantable cardioverter-defibrillators on the long-term prognosis of survivors of out-of-hospital cardiac arrest

BACKGROUND

Survivors of out-of-hospital cardiac arrest not associated with acute myocardial infarction are at high risk for recurrent cardiac arrest and sudden cardiac death. The impact of the implantable cardioverter-defibrillator on long-term prognosis in these patients is uncertain.

METHODS AND RESULTS

Three hundred thirty-one survivors of out-of-hospital cardiac arrest (age, 56 +/- 13.7 years) underwent electrophysiologically guided therapy. Implantable defibrillators were placed in 150 patients (45.3%), and 181 patients (54.7%) received pharmacological and/or surgical therapy alone. Left ventricular ejection fraction was 35.2 +/- 16.6% in defibrillator recipients and 45.3 +/- 18.2% in nondefibrillator patients. Median patient follow-up was 24 months in the defibrillator group and 46 months in the nondefibrillator group. In a proportional hazards model, the independent predictors of total cardiac mortality were left ventricular ejection fraction of less than 0.40 (relative risk, 4.55; 95% confidence interval, 2.44 to 8.33; P = .0001), absence of an implantable defibrillator (relative risk, 2.70; confidence interval, 1.41 to 5.00; P = .017), and persistence of inducible sustained ventricular tachycardia (relative risk, 1.84; 95% confidence interval, 0.97 to 3.49; P = .045). The 1- and 5-year probabilities of survival free of cardiac mortality in patients with left ventricular ejection fraction of less than 0.40 were 94.3% and 69.6% with a defibrillator and 82.1% and 45.3% without a defibrillator, respectively. For patients with left ventricular ejection fraction of 0.40 or more, the 1- and 5-year probabilities of survival free of cardiac mortality were 97.7% and 94.6% with a defibrillator and 95.4% and 86.9% without a defibrillator, respectively.

CONCLUSIONS

In survivors of out-of-hospital cardiac arrest, the implantable defibrillator is associated with a reduction in cardiac mortality, particularly in patients with impaired left ventricular function.