Evaluation of factors affecting awareness of and willingness to participate in cancer clinical trials.

PURPOSE: Annually, only 3% of patients participate in cancer clinical trials (CCTs). Barriers to accrual include lack of CCT awareness and uncertain third-party payer coverage. In January 2002, a California law (Senate Bill 37 [SB37]) required all third-party payers to reimburse patient care costs related to CCTs. We evaluated the level of awareness of patients and/or their family members/friends regarding CCTs and SB37. METHODS: We used both a written survey for patients and/or their family members and friends seen in oncology clinics, and a verbal telephone version for Cancer Information Service callers. We tested for correlations between CCT awareness and SB37 knowledge, and willingness to participate in CCTs. RESULTS: Of 1,188 respondents, 59% were aware of CCTs, 19% knew of SB37, and 36% were very likely to consider a CCT. There were significant positive correlations between CCT awareness and willingness to participate (P < .001, Spearman), and between SB37 knowledge and willingness to participate (P = .001, Pearson chi2). Reduced awareness was seen in respondents who were either black or African American (odds ratio [OR], 0.44; P = .004), Hispanic (OR, 0.56; P = .03), had an annual income less than 25,000 dollars (OR, 0.38; P < .001), or had less than a college degree (OR, 0.12 to 0.53; P < .001 to .013). Reduced willingness to participate in CCTs was seen in black or African American participants (OR, 0.38; P < .001), Asians (OR, 0.44; P < .006), or respondents aged 18 to 24 years (OR, 0.35; P = .002). CONCLUSION: These results support the hypothesis that improving CCT awareness and SB37 knowledge especially among lower income, less educated, and minority patients, may potentially overcome barriers to participation and subsequently increase accrual in California.

Tirapazamine plus carboplatin and paclitaxel in advanced malignant solid tumors: a california cancer consortium phase I and molecular correlative study.

PURPOSE: Tumor hypoxia confers chemotherapy resistance. Tirapazamine is a cytotoxin that selectively targets hypoxic cells and has supra-additive toxicity with platinums and taxanes in preclinical studies. We conducted a Phase I study of tirapazamine, carboplatin, and paclitaxel and assessed potential plasma markers of hypoxia as surrogates for response. EXPERIMENTAL DESIGN: Forty-two patients with advanced solid tumors were treated at four dose levels; parallel dose escalations were carried out in chemotherapy-naive and previously treated subjects. Pre and post-therapy plasma levels of the hypoxia-induced proteins plasminogen activator inhibitor-1 and vascular endothelial growth factor were measured. RESULTS: Three of four chemotherapy-naïve patients developed dose-limiting toxicities at dose level 4 (grade 3 stomatitis/infection, grade 3 emesis, and grade 4 febrile neutropenia). Four of seven previously treated patients developed dose-limiting toxicities at dose level 3, including one death [grade 3 myalgia, grade 3 infection/grade 4 neutropenia, grade 3 infection/grade 4 neutropenia, and grade 5 infection (death)/grade 4 neutropenia]. Of 38 patients assessable for response, 3 had a complete response, 1 a partial response, 1 an unconfirmed partial response, and 23 had stable disease in at least one evaluation; 10 quickly progressed. One complete responder had normalization of vascular endothelial growth factor and plasminogen activator inhibitor-1 levels. CONCLUSION: Dose levels 3 (carboplatin AUC of 6, 225 mg/m(2) paclitaxel, and 330 mg/m(2) tirapazamine) and 2 (carboplatin AUC 6, 225 mg/m(2) paclitaxel, and 260 mg/m(2) tirapazamine) are the maximum tolerated doses for chemotherapy naive and patients treated previously, respectively. Dose level 3 is the experimental arm of a Phase III Southwest Oncology Group trial (S0003) in advanced non-small cell lung cancer. Potential markers of tumor hypoxia may be useful correlates in studies of hypoxic cytotoxins and are being prospectively investigated in S0003.

Current strategies in the management of hormone refractory prostate cancer.

Prostate cancer is the most common cancer diagnosed in American males, and is the second leading cause of cancer-related deaths. Most patients who develop metastatic disease will initially respond to androgen deprivation, but response is invariably temporary. Most patients will develop androgen-independent ("hormone-refractory") disease that results in progressive clinical deterioration and ultimately death. This progression to androgen independence is accompanied by increasingly evident DNA instability and alterations in genes and gene expression, including mutations in p53, over-expression of Bcl2, and mutations in the androgen receptor gene, among others. Treatment options for hormone refractory disease include intensive supportive care, radiotherapy, bisphosphonates, second-line hormonal manipulations, cytotoxic chemotherapy and investigational agents. A post-treatment reduction in the level of prostate specific antigen (PSA) by 50% has been shown to correlate with survival and has been accepted by consensus as a valid endpoint in clinical trials. Chemotherapeutic agents such as mitoxantrone, estramustine, and the taxanes have yielded improved response rates and palliative benefit, but not improved survival. Therefore, current efforts must be focused on enrolling patients onto clinical trials of investigational agents with novel mechanisms of action, and on using survival, time to progression, and quality of life as end points in routine clinical practice.

Renal cell carcinoma: current status and future directions.

Although renal cell carcinoma accounts for only 3% of adult malignancies, it has been increasing in incidence by 2-4% per year since the 1970's. Cigarette smoking, obesity and end-stage renal disease are important risk factors. Genetic syndromes such as von Hippel-Lindau disease are also associated with an increased incidence of renal cell carcinoma. Localized disease should be treated with surgical resection. However, approximately 30% of patients present with metastatic disease. Complete resection of metastases can result in long-term survival in some individuals. Removal of the primary renal tumor in patients with unresectable disseminated disease has also been shown to improve survival in selected good performance status patients receiving systemic immunotherapy. While chemotherapy has been relatively ineffective in the treatment of renal cell carcinoma, biologic therapy with interleukin-2 or interferon does lead to responses in a minority of patients, with occasional long-term survivors. Recently, promising results have been reported with allogeneic stem cell transplantation using a non-myeloablative conditioning regimen. However, therapy for metastatic renal cell carcinoma remains inadequate. Ongoing trials with novel approaches such as anti-angiogenesis agents, cyclin-dependent kinase inhibitors, and tumor vaccines will hopefully lead to improved outcomes in this disease.

An evaluation of barriers to accrual in the era of legislation requiring insurance coverage of cancer clinical trial costs in California.

PURPOSE: Clinical trials are essential to improve cancer therapy, but only 3% of newly diagnosed adult cancer patients enroll annually. We previously conducted a prospective analysis of factors affecting trial accrual at the UC Davis Cancer Center between 1997 and 2000. It was found that the accrual rate was 14% and that patients with private insurance were significantly less likely than patients with government insurance to enroll, suggesting that fear of insurance denial was a barrier. In 2002, a new California law (SB37) required insurers to reimburse routine costs of care for cancer trials. METHODS: To assess the impact of SB37 on accrual, we repeated our study using the same sur vey instrument. Oncologists seeing new patients at the UC Davis Cancer Center from August to November 2002 completed questionnaires that inquired about patient characteristics and eligibility, protocol availability, and patient willingness to participate. RESULTS: Physicians considered clinical trials for 55% (118/216) of patients, but trials were available for only 53% (62/118). Eligibility criteria were met by 82% (51/62). Of these, 69% (35/51) agreed to participate (vs 51% previously). No patient declined to participate because of insurance limitations (vs 8% previously). Furthermore, insurance type was no longer a significant factor in determining whether patients would enroll. This suggests that although the overall rate of accrual is only slightly increased after passage of SB37, patients may be more willing to enroll. Efforts to increase participation must include enhancing physician and patient awareness of SB37.