Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations detected in case Series unselected for family history: a combined analysis of 22 studies

Germline mutations in BRCA1 and BRCA2 confer high risks of breast and ovarian cancer, but the average magnitude of these risks is uncertain and may depend on the context. Estimates based on multiple-case families may be enriched for mutations of higher risk and/or other familial risk factors, whereas risk estimates from studies based on cases unselected for family history have been imprecise. We pooled pedigree data from 22 studies involving 8,139 index case patients unselected for family history with female (86%) or male (2%) breast cancer or epithelial ovarian cancer (12%), 500 of whom had been found to carry a germline mutation in BRCA1 or BRCA2. Breast and ovarian cancer incidence rates for mutation carriers were estimated using a modified segregation analysis, based on the occurrence of these cancers in the relatives of mutation-carrying index case patients. The average cumulative risks in BRCA1-mutation carriers by age 70 years were 65% (95% confidence interval 44%-78%) for breast cancer and 39% (18%-54%) for ovarian cancer. The corresponding estimates for BRCA2 were 45% (31%-56%) and 11% (2.4%-19%). Relative risks of breast cancer declined significantly with age for BRCA1-mutation carriers (P trend.0012) but not for BRCA2-mutation carriers. Risks in carriers were higher when based on index breast cancer cases diagnosed at <35 years of age. We found some evidence for a reduction in risk in women from earlier birth cohorts and for variation in risk by mutation position for both genes. The pattern of cancer risks was similar to those found in multiple-case families, but their absolute magnitudes were lower, particularly for BRCA2. The variation in risk by age at diagnosis of index case is consistent with the effects of other genes modifying cancer risk in carriers.

Progesterone receptor variant increases ovarian cancer risk in BRCA1 and BRCA2 mutation carriers who were never exposed to oral contraceptives

Oral contraceptives have been shown to be protective against hereditary ovarian cancer. The variant progesterone receptor allele named PROGINS is characterized by an Alu insertion into intron G and two additional mutations in exons 4 and 5. The PROGINS allele codes for a progesterone receptor with increased stability and increased hormone-induced transcriptional activity. We studied the role of the PROGINS allele as a modifying gene in hereditary breast and ovarian cancer. The study included 195 BRCA1 and BRCA2 carriers with a prior diagnosis of ovarian cancer, 392 carriers with a diagnosis of breast cancer and 249 carriers with neither cancer. Fifty-eight women had both forms of cancer. Five hundred and ninety-five women had a BRCA1 mutation and 183 women had a BRCA2 mutation. Overall, there was no association between disease status and the presence of the PROGINS allele. Information on oral contraception use was available for 663 of the 778 carriers of BRCA1 or BRCA2 mutations. Among the 449 subjects with a history of oral contraceptive use (74 cases and 365 controls), no modifying effect of PROGINS was observed [odds ratio (OR) 0.8; 95% confidence interval (CI) 0.5-1.3]. Among the 214 carriers with no past exposure to oral contraceptives, the presence of one or more PROGINS alleles was associated with an OR of 2.4 for ovarian cancer, compared to women without ovarian cancer and with no PROGINS allele (P = 0.004; 95% CI 1.4-4.3). The association was present after adjustment for ethnic group and for year of birth.

Comparison of breast magnetic resonance imaging, mammography, and ultrasound for surveillance of women at high risk for hereditary breast cancer

PURPOSE

Recommended surveillance for BRCA1 and BRCA2 mutation carriers includes regular mammography and clinical breast examination, although the effectiveness of these screening techniques in mutation carriers has not been established. The purpose of the present study was to compare breast magnetic resonance imaging (MRI) with ultrasound, mammography, and physical examination in women at high risk for hereditary breast cancer.

PATIENTS AND METHODS

A total of 196 women, aged 26 to 59 years, with proven BRCA1 or BRCA2 mutations or strong family histories of breast or ovarian cancer underwent mammography, ultrasound, MRI, and clinical breast examination on a single day. A biopsy was performed when any of the four investigations was judged to be suspicious for malignancy.

RESULTS

Six invasive breast cancers and one noninvasive breast cancer were detected among the 196 high-risk women. Five of the invasive cancers occurred in mutation carriers, and the sixth occurred in a woman with a previous history of breast cancer. The prevalence of invasive or noninvasive breast cancer in the 96 mutation carriers was 6.2%. All six invasive cancers were detected by MRI, all were 1.0 cm or less in diameter, and all were node-negative. In contrast, only three invasive cancers were detected by ultrasound, two by mammography, and two by physical examination. The addition of MRI to the more commonly available triad of mammography, ultrasound, and breast examination identified two additional invasive breast cancers that would otherwise have been missed.

CONCLUSION

Breast MRI may be superior to mammography and ultrasound for the screening of women at high risk for hereditary breast cancer.

Psychosocial issues following a positive result of genetic testing for BRCA1 and BRCA2 mutations: findings from a focus group and a needs-assessment survey

BACKGROUND

About 5% of cases of breast cancer and 10% of cases of ovarian cancer are due to an inherited predisposition. Since 1994 it has been possible to test some people at high risk for inherited mutations to the BRCA1 and BRCA2 genes. The purpose of our study was to explore how genetic testing had affected people found to have a BRCA mutation and their families, and to determine whether there was interest in a peer-support group.

METHODS

All people given positive results of genetic testing for BRCA1 and BRCA2 mutations at either of 2 familial breast cancer clinics were invited to participate in a focus group and complete a questionnaire. Those who did not attend or who received positive results after the focus group were mailed the questionnaire. Information was sought on the effect of testing on cancer risk perception and worry about cancer, communication of test results to family members, attitudes toward surveillance and toward prevention options, satisfaction with clinical services, need for additional support and satisfaction with decision to undergo testing.

RESULTS

Eight of the 27 people invited to participate in the focus group attended. Sixteen of the 26 who were mailed the questionnaire completed and returned it. Although cancer risk perception and worry increased after receipt of the test results, the participants did not regret their decision to undergo testing. Confidence in the efficacy of cancer surveillance was high. Prophylactic oophorectomy was much more acceptable than prophylactic mastectomy. Almost all (92% [22/24]) were satisfied with the clinical services they had received; however, all were dissatisfied with the lengthy wait for test results. Nine (38%) of the participants felt they would benefit from a support group.

INTERPRETATION

Adequate resources must be made available to clinical programs providing BRCA1 and BRCA2 mutation testing to ensure appropriate pretest counselling and timely availability of results. Organization of support groups for people found to have the gene mutations should be a priority for these programs.

Phase I dose-finding and pharmacokinetic study of paclitaxel and carboplatin with oral valspodar in patients with advanced solid tumors

PURPOSE

To evaluate the maximum-tolerated dose (MTD), dose-limiting toxicities (DLTs), and pharmacokinetic (PK) profile of paclitaxel and carboplatin when administered every 3 weeks with the oral semisynthetic cyclosporine analog valspodar (PSC 833), an inhibitor of P-glycoprotein function.

PATIENTS AND METHODS

Fifty-eight patients were treated with escalating doses of paclitaxel ranging from 54 to 94.5 mg/m(2) and carboplatin area under the plasma concentration versus time curve (AUC) ranging from 6 to 9 mg.min/mL, every 21 days. The dose of valspodar was fixed at 5 mg/kg every 6 hours for a total of 12 doses from day 0 to day 3. The MTD was determined for the following two groups: (1) previously treated patients, where paclitaxel and carboplatin doses were escalated; and (2) chemotherapy-naïve patients, where paclitaxel dose was escalated and carboplatin AUC was fixed at 6 mg.min/mL. PK studies of paclitaxel and carboplatin were performed on day 1 of course 1.

RESULTS

Fifty-eight patients were treated with 186 courses of paclitaxel, carboplatin, and valspodar. Neutropenia, thrombocytopenia, and hepatic transaminase elevations were DLTs. In previously treated patients, no DLTs occurred at the first dose level (paclitaxel 54 mg/m(2) and carboplatin AUC 6 mg.min/mL). However, one of 12, two of six, two of four, four of 11, and two of five patients experienced DLTs at doses of paclitaxel (mg/m(2))/carboplatin AUC (mg.min/mL) of 67.5/6, 81/6, 94.5/6, 67. 5/7.5, and 67.5/9, respectively. In chemotherapy-naïve patients, one of 17 developed DLT at paclitaxel 81 mg/m(2) and carboplatin AUC 6 mg/mL.min. There was prolongation of the terminal phase of paclitaxel elimination as evidenced by an increased time that plasma paclitaxel concentration was >/= 0.05 micromol/L, ranging from 16.6 +/- 6.7 hours to 41.5 +/- 9.8 hours for paclitaxel doses of 54.5 mg/m(2) to 94.5 mg/m(2), respectively.

CONCLUSION

The recommended phase II dose in chemotherapy-naïve patients is paclitaxel 81 mg/m(2), carboplatin AUC 6 mg.min/mL, and valspodar 5 mg/kg every 6 hours. In previously treated patients, the recommended phase II dose is paclitaxel 67.5 mg/m(2), carboplatin AUC 6 mg.min/mL, and valspodar 5 mg/kg every 6 hours. The acceptable toxicity profile supports the rationale for performing disease-directed evaluations of paclitaxel, carboplatin and valspodar on the schedule evaluated in this study.

Perceptions of Ashkenazi Jewish breast cancer patients on genetic testing for mutations in BRCA1 and BRCA2

The perceived benefits and risks of genetic testing may vary between groups of individuals with different cultural, demographic, and family history features. This multicentre study examined the factors that influenced the decision to undergo genetic testing for BRCA1 and BRCA2 in Canadian Jewish women with breast cancer. A self-administered questionnaire was developed and distributed to 134 individuals enrolled in a research-based testing program for Ashkenazi women. The questionnaire assessed demographic, social, and family history parameters, and the influence of medical, family, social, psychological, and cultural/religious factors on decision making about genetic testing. Seventy-six percent of women completed the questionnaire. Forty-one percent of study participants had no family history of breast or ovarian cancer. The most important factors influencing the decision to undergo testing were a desire to contribute to research, potential benefit to other family members, curiosity, and the potential for relief if not found to be a carrier (endorsed by 87, 78, 70, and 60% of participants, respectively). The main perceived risks of undergoing genetic testing related to insurance discrimination, confidentiality, accuracy and interpretability of results, potential impact on marriage prospects for family members, and focus on the Jewish community (endorsed by 28, 24, 30, 17, and 14% of participants, respectively). This study provides novel information on the motivating factors for BRCA1 and BRCA2 mutation testing in Canadian women of Ashkenazi Jewish descent. The focus on altruistic factors and those related to perceived psychological benefits of testing is notable.

Prevalence of BRCA1 and BRCA2 mutations in male breast cancer patients in Canada

Men who inherit a mutation in the BRCA2 gene carry a 6% risk of developing breast cancer by the age of 70. The proportion of male breast cancers attributable to BRCA mutations has not yet been determined with accuracy. We studied a series of 14 male breast cancer patients, unselected for family history or ethnicity, who were treated at a single regional cancer center in Canada. Family histories were obtained, and the men were tested for germ-line mutations of BRCA1 and BRCA2. Seven of these patients had a significant family history of breast cancer (i.e., at least one first- or second-degree relative with breast cancer diagnosed before age 70). Two of the men carried BRCA2 mutations, but no BRCA1 mutations were found. Both mutation carriers reported a positive family history and a personal history of cancer that preceded their diagnosis of breast cancer. Our results support the recommendation that male breast cancer patients who have a significant family history of breast or ovarian cancer should be offered genetic counseling and testing.

BRCA1 and BRCA2 mutation analysis of 208 Ashkenazi Jewish women with ovarian cancer

Ovarian cancer is a component of the autosomal-dominant hereditary breast-ovarian cancer syndrome and may be due to a mutation in either the BRCA1 or BRCA2 genes. Two mutations in BRCA1 (185delAG and 5382insC) and one mutation in BRCA2 (6174delT) are common in the Ashkenazi Jewish population. One of these three mutations is present in approximately 2% of the Jewish population. Each mutation is associated with an increased risk of ovarian cancer, and it is expected that a significant proportion of Jewish women with ovarian cancer will carry one of these mutations. To estimate the proportion of ovarian cancers attributable to founding mutations in BRCA1 and BRCA2 in the Jewish population and the familial cancer risks associated with each, we interviewed 213 Jewish women with ovarian cancer at 11 medical centers in North America and Israel and offered these women genetic testing for the three founder mutations. To establish the presence of nonfounder mutations in this population, we also completed the protein-truncation test on exon 11 of BRCA1 and exons 10 and 11 of BRCA2. We obtained a detailed family history on all women we studied who had cancer and on a control population of 386 Ashkenazi Jewish women without ovarian or breast cancer. A founder mutation was present in 41.3% of the women we studied. The cumulative incidence of ovarian cancer to age 75 years was found to be 6.3% for female first-degree relatives of the patients with ovarian cancer, compared with 2.0% for the female relatives of healthy controls (relative risk 3.2; 95% CI 1.5-6.8; P=.002). The relative risk to age 75 years for breast cancer among the female first-degree relatives was 2.0 (95% CI 1.4-3.0; P=.0001). Only one nonfounder mutation was identified (in this instance, in a woman of mixed ancestry), and the three founding mutations accounted for most of the observed excess risk of ovarian and breast cancer in relatives.

Evidence of a founder BRCA1 mutation in Scotland

BRCA1 mutations have been identified in breast and ovarian cancer families from diverse ethnic backgrounds. We studied 17 different families with the BRCA1 2800delAA mutation; seven were ascertained in Scotland (Dundee, Edinburgh, Glasgow, St Andrews), five in Canada (Toronto, Victoria) and five in the United States (Chicago, Philadelphia, Seattle). Overall there was a clear preponderance of Scottish ancestry. Genotype analysis performed on key members from 17 families was consistent with a common haplotype, strongly suggesting a single ancestral origin. A possible link was established between two families by tracing their genealogies through the records of the Registrar General for Scotland. This is the first example of a BRCA1 mutation likely to be derived from a common founder in Scotland. Further studies will be necessary to estimate more accurately the population frequency of the BRCA1 2800delAA mutation among unselected cases of breast and ovarian cancer in Scotland and the UK.

Pregnancy and risk of early breast cancer in carriers of BRCA1 and BRCA2

BACKGROUND

Early age at first full-term pregnancy and increasing parity are associated with a reduced risk of breast cancer. However, whether pregnancy decreases the risk of early-onset hereditary breast cancer is unknown. There is concern that pregnancy may increase breast-cancer risk in carriers of BRCA1 and BRCA2 germline mutations. We aimed to establish whether pregnancy is a risk factor for hereditary breast cancer.

METHODS

We did a matched case-control study of breast cancer in women who carry deleterious BRCA1 or BRCA2 mutations. Cases were carriers who developed breast cancer by age 40 years, and controls were carriers of the same age without breast cancer, or who were diagnosed with breast cancer after age 40 years. Women who had undergone preventive mastectomy, hysterectomy, or oophorectomy, or who were diagnosed with ovarian cancer before the age at which breast cancer was diagnosed in the matched case were excluded. Information about pregnancies and pregnancy outcome was derived from a questionnaire completed by women in the course of genetic counselling.

FINDINGS

A higher proportion of cases than controls had had a full term pregnancy (173/236 vs 146/236; odds ratio 1.71 [95% CI 1.13-2.62], p=0.01). The mean number of births was also greater for cases than for controls (1.62 vs 1.38, p=0.04). The risk increased with the number of births and did not diminish with time since last pregnancy. There were no significant differences in age at first birth or age at last birth between cases and controls.

INTERPRETATION

Carriers of the BRCA1 and BRCA2 mutations who have children are significantly more likely to develop breast cancer by age 40 than carriers who are nulliparous. Each pregnancy is associated with an increased cancer risk. An early first pregnancy does not confer protection for carriers of BRCA1 or BRCA2 mutations.

Prevalence and penetrance of BRCA1 and BRCA2 gene mutations in unselected Ashkenazi Jewish women with breast cancer

BACKGROUND

Approximately 2.0%-2.5% of Ashkenazi Jewish women carry one of three founding mutations in the BRCA1 and BRCA2 genes, and each mutation is associated with a high lifetime risk of invasive breast cancer. We investigated the extent to which these three mutations contribute to breast cancer incidence in the Ashkenazi Jewish population.

METHODS

We ascertained 457 Jewish women with prevalent cases of breast cancer who were unselected for age or family history of the disease; 412 of these women were tested for the three founder mutations (case patients). Control subjects consisted of 360 non-Jewish women with breast cancer (control patients) and 380 healthy Jewish women with no history of cancer (control subjects).

RESULTS

Mutations were found in 48 (11.7%) of 412 Jewish case patients. Forty-six of 48 mutations occurred in women with early-onset breast cancer (<50 years) or a history of ovarian or early-onset breast cancer in a first-, second-, or third-degree relative. The estimated penetrance to age 70 years for breast cancer was 59.9% for the BRCA1 gene mutations and 28.3% for the BRCA2 gene mutation. Compared with Jewish control subjects, the relative risk (RR) of breast cancer for first-degree relatives of mutation carriers was 5.16 (95% confidence interval [CI] = 3.14-8. 48), but risk was also increased for relatives of noncarriers (RR = 1.66; 95% CI = 1.18-2.33). The RR of prostate cancer for first-degree relatives of Jewish case patients was 3.36 (95% CI = 1. 49-7.56).

CONCLUSIONS

Approximately 12% of breast cancers in the Ashkenazi Jewish population are attributable to mutations in the BRCA1 or BRCA2 gene. Genetic testing may be useful when Jewish women with breast cancer are diagnosed before age 50 years or have a close relative with ovarian or early-onset breast cancer. An association between breast and prostate cancers was observed in our study population.

Outpatient 5-fluorouracil, folinic acid and cisplatin in patients with advanced esophageal carcinoma

In a multicenter phase II study, 30 patients with unresectable, locally advanced or metastatic squamous cell or adenocarcinoma of the esophagus were treated with folinic acid 200 mg/m2/d, 5-FU 300 mg/m2/d, and cisplatin 20 mg/m2/d intravenously for 5 days every 4 weeks. Two of 13 patients with squamous cell carcinoma (SCC) had a complete response (CR), but one died of pneumonia after 9 months while still in CR, and the other still in CR after more than 5 years. Six other patients (3 SCC, 2 of 16 with adenocarcinoma, 1 mixed histology) had a partial response with a median duration of 9 months (range 5 to 57 + months) for an overall response rate of 27%. A further 6 patients (20%) had stable disease. Grade 4 neutropenia occurred in 6 patients (20%), with 5 requiring antibiotics for associated fever. Other grade 4 toxicities were nausea and vomiting (1), anemia (1), and thrombocytopenia (1); there were three early deaths (emphysema, cardiac arrest, pulmonary embolism). This combination appears to be an active, convenient regimen for advanced esophageal cancer, resulting in prolonged remission and survival in some patients.

Hereditary breast cancer. Psychosocial issues and family physicians' role

OBJECTIVES

To outline the psychosocial issues in hereditary breast cancer (HBC) assessment and discuss the role of family physicians.

QUALITY OF EVIDENCE

A literature search using MEDLINE, CINAHL, CancerLit, and HealthStar databases was conducted from January 1990 to April 1998, using the key words breast cancer or neoplasm and familial or hereditary, genetic testing or screening, primary care or family physician or counseling, genetic counseling, psychosocial or psychological. We found only a few studies focusing on a small number of well-studied "research families."

MAIN FINDINGS

Women with a family history of breast cancer were likely to be highly interested in genetic testing for cancer risk. The benefit of testing for those with negative results is reassurance. Those found to be carriers of genetic mutations might benefit from increased surveillance and prophylactic therapy. Risks of testing include anxiety, depression, guilt, altered self-image, and insurance and employment discrimination. A family physician's role is to assess risk, to provide information and support so women can make informed choices about referral to familial cancer clinics, to offer cancer surveillance, and to provide support once genetic test results are available.

CONCLUSION

Genetic testing is rapidly moving from research to clinical applications. Family physicians play an integral role in educating and managing women at risk for HBC. Physicians must prepare themselves with knowledge and counseling skills to meet the challenges of this new technology.

Hereditary breast cancer. Risk assessment of patients with a family history of breast cancer

OBJECTIVES

To assist family physicians in stratifying women with a family history of breast cancer as being at low, moderate, or high risk of hereditary breast cancer (HBC). To present guidelines for managing each of these risk groups.

QUALITY OF EVIDENCE

A MEDLINE search was conducted from January 1976 to December 1997 using key words related to breast cancer risk factors, risk assessment, prevention, and screening. Risk stratification criteria were derived empirically and assessed using retrospective chart review.

MAIN FINDINGS

Although up to 20% of women in the general population have a family history of breast cancer, less than 5% are at high risk for HBC. Certain features in a family history suggest increased risk. Women with none of these features are at low risk for HBC and should have annual clinical breast examinations and mammography at least every 2 years starting at age 50. Women with one or more features of increased risk who do not meet criteria for referral to a familial cancer clinic are at moderate risk for HBC and should begin annual mammography and clinical breast examination at age 40. Women who meet referral criteria are at high risk for HBC and should be counseled regarding referral to a familial cancer clinic for more detailed risk assessment and consideration for genetic testing. All women should be taught proper breast self-examination technique and encouraged but not pressured to practise it monthly for life.

CONCLUSION

A simple algorithm can assist physicians in stratifying women into low, moderate, and high HBC risk groups. Management strategies for each group are given in this article and the two following (Heisey et al page 114 and Carroll et al page 126).

Hereditary breast cancer. Identifying and managing BRCA1 and BRCA2 carriers

OBJECTIVES

To present a strategy for identifying candidates for consideration of BRCA1 and BRCA2 mutation testing. To discuss the implications of identifying patients as BRCA1 or BRCA2 mutation carriers, and to provide recommendations for managing them.

QUALITY OF EVIDENCE

A MEDLINE search from January 1990 to May 1998 was performed using the terms genetic breast screening, BRCA1, and BRCA2. The bibliographies of articles found were searched for further relevant titles. There are no published, randomized controlled clinical trials of management strategies for known BRCA carriers. Many recommendations for management are based on expert opinion only.

MAIN FINDINGS

About 5% of women with breast cancer are carriers of genetic mutations. An accurate and detailed family history is the most important tool for identifying potential BRCA1 and BRCA2 mutation carriers. Women identified as carriers have a substantially increased risk of breast and ovarian cancer. Male carriers have a moderately increased risk of prostate cancer. Management strategies for carriers are not well studied but include increased surveillance, preventive surgery, chemoprevention, and lifestyle modification.

CONCLUSION

Family physicians must be able to identify people at risk, to discuss management strategies, and when appropriate, to offer referral for consideration of genetic testing. There is an urgent need for research to determine the effectiveness of surveillance strategies, preventive surgery, chemoprevention, and lifestyle modification for BRCA1 and BRCA2 mutation carriers.

Development of a knowledge scale about breast cancer and heredity (BCHK)

An 11-item questionnaire, the Breast Cancer and Heredity Knowledge Scale (BCHK), was developed to test general knowledge about breast cancer and hereditary breast cancer (HBC) among women at low to moderate risk of HBC. The BCHK measures knowledge about breast cancer incidence and prognosis, risk factors, screening, disease presentation and treatment, and HBC. Scale items were generated from focus group interviews, previously published breast cancer knowledge scales, and consultation with a multidisciplinary research team, including health professionals and women with breast cancer or a family history of breast cancer. A 27-item draft scale was tested on 36 breast clinic patients and 17 women from the general public. Results were used to develop the final 11-item scale. Development of the scale and its potential uses are discussed.

A multicentre phase II study of carboplatin and prolonged oral etoposide in the treatment of cancer of unknown primary site (CUPS)

Cisplatin-based combination chemotherapy is frequently used to treat patients with carcinoma of unknown primary site (CUPS). Response rates in the literature range from 12% to 26% and median survival from 5 to 7 months. The goal of this study was to evaluate the combination of carboplatin and prolonged oral etoposide in patients with CUPS, with the hope of minimizing toxicity but improving efficacy and convenience. Treatment consisted of carboplatin, 300 mg m(-2) on day 1, and oral etoposide 50 mg on days 1-20, every 4 weeks for up to nine cycles. A total of 33 patients were treated and all were evaluable for toxicity. Non-haematological toxicity was mild to moderate, with the exception of one case of grade 4 stomatitis. Grade 4 leucopenia was observed in eight (24%) patients and sepsis in four (12%), with two and possibly three treatment-related deaths. For the 26 patients evaluable for response, the response rate was 23% with responses lasting a median of 11 months (range 7-13 months), with one patient still responding at 12 months. An additional nine patients (35%) had stable disease. Median survival for all patients was 5.6 months (range 2 weeks to 33 months). The combination of carboplatin with prolonged oral etoposide has moderate activity similar to that of other platinum-based regimens and is a well tolerated, convenient, outpatient regimen. Dosing according to estimated creatinine clearance to achieve a carboplatin AUC of 6.0 mg ml(-1) min might have decreased the incidence of severe myelotoxicity without compromising the regimen's efficacy.

Phase II study of dexverapamil plus anthracycline in patients with metastatic breast cancer who have progressed on the same anthracycline regimen

The purpose of this study is to evaluate whether metastatic breast cancer that has progressed on an anthracycline-containing drug regimen will subsequently respond to that identical regimen if dexverapamil, a modulator of P-glycoprotein-mediated drug resistance, is given concomitantly. Eligible patients received 180 mg/m2 dexverapamil every 6 h for 15 doses with the anthracycline administered 30 min after the seventh dose. Blood for dexverapamil levels was drawn before and 30 min after this dose. When possible, biopsies were obtained to measure mdr-1 expression by reverse transcription-PCR and by image cytometry. Of the 21 patients entered onto the trial, 20 were evaluable for response. There were two partial responses (10%) that both lasted for 6 months, and two additional patients had stable disease. Seven patients had asymptomatic cardiotoxicity consisting of hypotension (24%), bradycardia (5%), or prolongation of the P-R interval (14%). Two patients developed acute congestive heart failure, one on dexverapamil and one 10 days after stopping it. Dexverapamil did not seem to increase anthracycline toxicity. The median trough dexverapamil plus norverapamil level on day 3 was 1110 ng/ml (range, 186-3385 ng/ml), and the median peak level was 2164 ng/ml (range, 964-8382 ng/ml). There was poor correlation between reverse transcription-PCR and image cytometry for the level of mdr-1 expression. Because dexverapamil has been shown to affect doxorubicin pharmacokinetics subsequent to the initiation of this trial, it cannot be concluded that the responses seen were necessarily due to P-glycoprotein inhibition. Additional studies are necessary to determine whether mdr-1 modulators can reverse clinical drug resistance in breast cancer patients. The intrinsic cardiotoxicity of dexverapamil makes it less suitable for such studies than several other available agents.

Salvage chemotherapy with cladribine in a patient with recurrent malignant oligodendroglioma

Oligodendrogliomas appear to be the most chemoresponsive subtype of gliomas. PCV (procarbazine, CCNU, vincristine) chemotherapy produces significant response rates and probable prolongation of survival. Unfortunately there is no well-defined second line chemotherapy. There is evidence that the purine analogue cladribine has activity in astrocytomas, which are much less sensitive to chemotherapy than oligodendrogliomas, but the use of cladribine in oligodendrogliomas has never been reported. We describe the unsuccessful use of cladribine as third line chemotherapy in a young man with an aggressive oligodendroglioma. The literature pertaining to chemotherapy for oligodendrogliomas is reviewed.