Sequential Therapies and the Cost-Effectiveness of Treating Metastatic Colon Cancer Patients.

BACKGROUND: Technological advances in colon cancer treatment have significantly increased survival outcomes among metastatic patients. With different chemotherapy and biologic regimens administered in first, second, and subsequent lines of treatments, costs and survival outcomes vary considerably. However, there is little evidence on how the type of regime administered in the first line of treatment affects the costs and survival outcomes of the second line of treatment. OBJECTIVE: To examine how the cost-effectiveness of second-line treatment for elderly metastatic colon cancer patients varies by the type of regimen administered in the first line of treatment. METHODS: The Surveillance, Epidemiology and End Results (SEER) cancer registry was used, which is linked with the Medicare claims database, to study elderly metastatic patients diagnosed between 2003 and 2009. Average survivals are estimated using the robust nonparametric Kaplan-Meier method. Selection bias was adjusted for using inverse probability weighting and censoring using robust nonparametric methods of estimating the average of total health care costs. RESULTS: Mean incremental survival was 6.7 months for patients who received second-line treatment (95% CI = 5.7-7.7) compared with those receiving only first-line treatment. However, the mean incremental survival varied between 4 months (95% CI = 0.0-7.3) and 9 months (95% CI = 6.5-11.0) depending on whether fluorouracil with or without leucovorin, irinotecan, oxaliplatin, or other agents were administered in first-line treatment. The mean incremental cost associated with receipt of second-line treatment was $60,231 (95% CI = 52,461-64,198) but ranged between $55,368 (95% CI = 48,294-61,290) and $71,211 (95% CI = 43,168-99,667), depending on the type of regimen administered in the first-line treatment. Combining survival benefits and costs, the incremental cost-effectiveness ratios per life-year gained associated with the receipt of second-line treatment were $97,368 (95% CI = 80,415-117,965); $110,621 (95% CI = 89,560-133,961); $130,689 (95% CI = 101,459-171,918); and $247,951 (95% CI = 112,629808,976) when irinotican, fluorouracil/leucovorin, oxaliplatin, and "other" combinations were, respectively, administered in first-line treatment. In addition, the results varied depending on which statistical method was used. CONCLUSIONS: When therapies are administered in a sequential manner, the cost-effectiveness of the second line of therapy depends on what was administered in the first line of therapy. DISCLOSURES: Bayer Healthcare Pharmaceuticals provided funding for this project. Onukwugha has received research funding from Bayer and Amgen and has a consultant/advisory relationship with Jansen Analytics at Johnson & Johnson. Seal was formerly an employee of Bayer and holds stock in Bayer. Mullins has research funding sponsored by Bayer and Pfizer and has a consultant/advisory relationship with Bayer, Amgen, BMS, Genentech, GSK, Novartis, NovoNordisk, and Pfizer. Woldemichael and Nader report no conflicts of interest. All authors contributed to the concept and design of this study. Onukwugha, Seal, and Mullins collected the data, with assistance from Woldemichael and Hanna, while Woldemichael interpreted the data, assisted by the other authors. The manuscript was written primarily by Woldemichael, with assistance from the other authors, and revised by Seal, Hanna, and Mullins, with assistance from Woldemichael and Onukwugha.

Patterns of Biologics Use Across Treatment Lines in Elderly (Age >65) Medicare Patients With Metastatic Colon Cancer.

BACKGROUND: We explored biologics receipt in metastatic colon cancer. METHODS: We used Surveillance, Epidemiology, and End Results-Medicare data of 4,545 elderly patients diagnosed with incident metastatic colon cancer from 2003 to 2009, treated with chemotherapy and/or biologics, and followed up through 2010. RESULTS: A total of 2,504 (55%) patients received a biologics-containing regimen. Treatment with biologics fluctuated between 46% and 63% of first-line regimens and 67% and 73% of second-line regimens. Bevacizumab accounted for 95% of first-line and 68% of second-line biologics use. Cetuximab accounted for 33% of second-line and 48% of third-line use. Panitumumab accounted for 5% of second-line and 27% of third-line use. The adjusted odds of biologics receipt decreased rapidly with age, resulting in a threefold difference between the youngest and the oldest study participants in the sample (odds ratio [OR] 0.35, p < .01). African Americans (OR 0.77, p = .03) and patients with Charlson Comorbidity Index of 1 (OR 0.83, p = .02) or >1 (OR 0.75, p < .01) were considerably less likely to receive biologics therapy. Medicare state buy-in was associated with 2% lower odds of receiving biologics (OR 0.98, p = .04). CONCLUSION: After controlling for sociodemographic and clinical differences, age, race, comorbidities, and low income had a statistically significantly negative effect on the likelihood of receiving biologics among treated patients. Use of biologics varied over time, across the treatment continuum, and by chemotherapy regimen. Bevacizumab was most frequently used in both first- and second-line treatment. Cetuximab was the second most prescribed biologic. Panitumumab use was mostly limited to third-line treatment. IMPLICATIONS FOR PRACTICE: It is well-known that patients in the "real world" receive cancer treatments that do not reflect the strict treatment protocols of clinical trials. This is particularly true for complex and elderly patients with metastatic disease, who are frequently underrepresented in clinical trials. Although this article does not provide any additional evidence about the effectiveness of one treatment regimen or treatment sequence over another, it enhances our understanding of oncology practice outside of the clinical trial setting and provides useful information for future health services and health economics research in metastatic colon cancer.

Algorithm for identifying chemotherapy/biological regimens for metastatic colon cancer in SEER-Medicare.

BACKGROUND: Metastatic colon cancer (mCC) patients often receive multiple lines of chemotherapy/biological treatment (TX), yet subsequent TX lines have not been sufficiently examined using SEER-Medicare data. We developed an algorithm that identifies the number and type of TX lines received by mCC patients. METHODS: The algorithm rules for detecting TX lines were developed a priori and applied to SEER-Medicare data for 7951 elderly mCC patients, diagnosed in 2003-2007 and followed through 2009. Statistical analysis estimated the relationship between the number of treatments received and patient characteristics. Sensitivity analyses examined how results changed when different algorithm rules were used. RESULTS: Only 41% (3266) of mCC patients received any chemotherapy/biologics treatment; 1440 (18% of all, 44% of treated) and 274 (3% of all, 8% of treated) received second-line and third-line treatment, respectively. Initial and subsequent treatment regimens varied widely. Results were robust to alterations in the algorithm. CONCLUSIONS: The number of drugs used to treat cancer patients has increased during the past decade. Patients may have several TX lines with complex regimens. More guidance is needed with regard to identifying and studying these interventions using SEER-Medicare data. By proposing 1 approach to categorizing TX lines for mCC patients, we hope to empower the scientific community and to advance the use of SEER-Medicare data for health outcomes research.

Multispecialist Care and Mortality in Hepatocellular Carcinoma.

PURPOSE: Multidisciplinary physician care has increased for many cancers yet little evidence exists for hepatocellular carcinoma (HCC). The purpose of this study was to explore the association between multispecialist care and mortality in HCC. METHODS: Treated patients with an HCC primary diagnosis from 2000 to 2007 were studied using Surveillance, Epidemiology, and End Results-Medicare data. A surrogate variable for multidisciplinary care was defined-multispecialist care-as the number of disciplines among surgeons, radiology oncologist, intervention radiologist, hematologist/medical oncologist, gastroenterologist, and generalist in the pretreatment period. Multivariate survival analysis was conducted and adjusted for selection and survival bias. RESULTS: Of 3588 treated HCC patients, 1434 (40%) saw 1, 1343 (37%) saw 2, and 811 (23%) saw 3 or more specialists. Patients with multispecialist care received treatment that differed from patients who saw a single specialist. In propensity score-adjusted survival analysis, patients who saw 3 or more specialist types were associated with 10% (P=0.04) reduced mortality, compared with those who saw 1 specialist. When stratified by treatment received, patients on chemotherapy who saw 3 or more specialist types were associated with 28% (P=0.002) reduced mortality, compared with those who saw 1 specialist. CONCLUSIONS: Multispecialist care for treated HCC patients was associated with reduced mortality, particularly among chemotherapy recipients. While adjusting for selection and survival bias, our study is limited in capturing a causal relationship between coordinated multidisciplinary care and mortality. Our findings may provide support for the development of coordinated care delivery models but should be confirmed through more rigorous examination in future studies.

Cost-effectiveness of second-line chemotherapy/biologics among elderly metastatic colon cancer patients.

INTRODUCTION: Advancements in chemotherapy treatment have improved the clinical management of metastatic colon cancer (mCC) patients. An increasing number of elderly mCC patients receive various combinations of regimens in second-line chemotherapy/biologics treatment (Tx2) after first-line treatment (Tx1) to prolong survival and/or palliate symptoms, but these regimens have higher costs. This analysis investigated the survival benefit and incremental cost associated with Tx2 among elderly mCC patients. METHODS: Elderly (aged ≥66 years) SEER-Medicare patients diagnosed with mCC in 2003-2007 were identified and followed until death or the end of 2009. Cox regression and partitioned least squares regression were utilized to obtain the survival benefit and incremental cost associated with Tx2 within a 5-year study period. A time-varying model was used to reduce bias due to sequential ordering of Tx1 and Tx2. The regressions controlled for patient demographic characteristics, clinical variables, and a proxy for poor performance. Bootstrapping was used to generate 95% confidence intervals (CI). RESULTS: Of the 3,266 elderly mCC patients who received Tx1, 2,744 (84%) died within the observation period; 1,440 (44%) received Tx2. The survival benefit associated with receipt of Tx2 was 0.33 years (95% CI 0.19-0.43), and the associated incremental cost was $40,888 (95% CI 3,044-44,324). The incremental cost-effectiveness ratio (ICER) for Tx2 was $123,903 per life year gained (95% CI 9,600-216,082). CONCLUSION: The estimated survival benefit of receiving second-line chemotherapy/biologics was about 4 months, which is consistent with evidence from clinical trials. This improved survival was associated with an ICER that exceeds the traditional threshold.

Does the type of first-line regimens influence the receipt of second-line chemotherapy treatment? An analysis of 3211 metastatic colon cancer patients.

With new agents entering the market, the sequencing of first-line (Tx1), second-line (Tx2), and subsequent chemotherapy/biologics regimens are being examined. We examined how Tx1 regimens impacted the likelihood of receiving Tx2 among metastatic colon cancer (mCC) patients. Surveillance, Epidemiology and End Results (SEER)-Medicare data were used to identify elderly mCC patients between 2003 and 2007. The inverse probability weighting Cox regression method was utilized to study the relationship between receipt of Tx2 and Tx1 regimens, controlling for patient-level factors. Of the 7895 elderly patients identified, 3211 (41%) received Tx1 of which 1440 proceeded to Tx2. The impact of Tx1 on receipt of Tx2 varied by the specific regimens utilized. As compared to 5FU/LV users, IROX (Hazard Ratio [HR] = 0.03; P < 0.01) and IROX + Biologics (HR = 0.20; P < 0.01) users were less likely to receive Tx2; (oxaliplatin) OX + Biologics (HR = 1.26; P < 0.01) users were more likely to receive Tx2. Significant patient-level factors included: Hispanic ethnicity (HR = 0.67; P < 0.01); being married (HR = 0.87; P = 0.01); proxy for poor performance status (HR = 0.82; P = 0.05); each 10-year age increment (HR = 1.14; P < 0.01); and State buy-in status (HR = 1.21; P = 0.01). The specific first-line regimen does impact mCC patients' likelihood of receiving Tx2 in clinical practice. Elderly mCC patients, their health care providers, and policy makers will benefit from new evidence about the impact of sequencing of treatment lines.

Comparative and cost effectiveness of treatment modalities for hepatocellular carcinoma in SEER-Medicare.

BACKGROUND: The incidence of hepatocellular carcinoma (HCC) is increasing in the USA and worldwide. Several treatments are available for patients diagnosed at any disease stage. It remains unclear how medical expenditures vary across patients who remain untreated or undergo different modes of therapy. We evaluate the comparative and cost effectiveness of treatment modalities for HCC from a Medicare perspective. METHODS: The Surveillance, Epidemiology, and End Results (SEER) registries and linked Medicare database with claims from Parts A/B were used to identify Medicare enrollees with initial diagnosis of HCC between 2000 and 2007 and followed through 2009. Patients were assigned to treatment modalities based on HCC staging systems: transplant, resection, liver directed, radiation, chemotherapy or no treatment. Survival benefits and cumulative Medicare expenditures were estimated in multivariate models, stratified by initial disease stage, to control for confounding. Cost-effectiveness ratios compared costs and benefits of the modalities across initial stages. RESULTS: Cancer stages I, II, III, IV and unstaged represented 24, 9, 14, 17 and 37 % of 11,047 patients, respectively. Fewer than 40 % received any treatment. Relative to no treatment, transplant was most effective in reducing mortality, followed by resection, liver directed, and radiation or chemotherapy. Resection tended to be most cost effective in early staged and unstaged patients; transplant was least cost effective. In stage IV patients, liver directed therapy was more cost effective than chemotherapy or radiation. CONCLUSIONS: Survival benefit was attributable to all treatment modalities. More effective treatments incurred greater Medicare expenditures, but resection patients incurred the least expenditures per year of life gained.

Transarterial chemoembolization treatment: association between multiple treatments, cumulative expenditures, and survival.

OBJECTIVES: To examine cumulative survival and Medicaid-paid expenses associated with multiple courses of transarterial chemoembolization (TACE) as primary treatment for hepatocellular carcinoma (HCC). METHODS: Medicare enrollees diagnosed with primary HCC from 2000 to 2007, ever treated with TACE, but not transplant/resection, followed through 2009 by using the Surveillance, Epidemiology and End-Results Program and linked Medicare databases. Cumulative all-cause/HCC-related survival was estimated by using multivariate Cox proportional hazards models stratified by the total number of TACE treatments. Multivariate weighted Cox regressions estimated the average risk of mortality faced with nonproportional hazards. Lin's inverse probability-weighted least squares regression method estimated cumulative Medicare expenditures adjusted for censoring and covariates. RESULTS: Of 1228 patients, 34% were stage 1, 16% stage 2, 19% stage 3, 6% stage 4, and 26% unstaged. About 44% were aged 65 to 75 years, 69% were men, and 72% were Caucasian. Over half (57%) of the patients received one course, 24% two, 11% three, and 8% four courses of TACE. One-course patients incurred an average $74,788 (95% confidence interval [CI] $71,890-$77,686), two-course patients $101,126 (95% CI $94,395-$107,856), three-course patients $111,776 (95% CI $101,931-$121,621), and four-plus-course patients $148,878 (95% CI $136,346-$161,409). One-course patients lived (all-cause) an average 1.86 (95% CI 1.82-1.90), two-course patients 2.09 (95% CI 2.05-2.13), three-course patients 2.81 (95% CI 2.66-2.97), and four-plus-course patients 3.06 (95% CI 2.95-3.18) years after diagnosis. Average risk of all-cause mortality was not significantly different between one/two courses or three/four-plus courses. CONCLUSIONS: Cumulative Medicare expenditures nearly doubled from one-course to four-plus-course patients. On average, four-plus-course patients lived over one more year than did one-course patients. Physician/patient decisions should be balanced with consideration of efficient use of limited resources, but payer's intervention in physician discretion may not be important in this setting.

Assessment of neoadjuvant chemotherapy on operative parameters and outcome in patients with peritoneal dissemination from high-grade appendiceal cancer.

BACKGROUND: High-grade appendiceal adenocarcinoma is a rare malignancy with propensity for peritoneal metastases (PM). The impact of neoadjuvant chemotherapy on operative cytoreduction (CRS) and intraperitoneal chemotherapy (HIPEC) and patient survival was reviewed. METHODS: A total of 45 patients with PM from high-grade appendiceal adenocarcinoma were identified from a prospective database. All patients had laparotomy with intent to undergo CRS and HIPEC. Operative parameters, complications, and survival outcomes were analyzed. RESULTS: Of the 45 patients (male: 27, female: 18; median age: 55 years), 26 received neoadjuvant chemotherapy ± bevacizumab. Of the 26, 15 (58 %) had a response based on improvement in imaging, biomarkers, or both and 9 (34 %) had stable disease. The median peritoneal cancer index (PCI) was 27. Also, 30 (67 %) had a completeness of cytoreduction score (CCR) of ≤1 and 37 (82 %) received HIPEC. There were no differences in PCI, CCR score, operative blood loss, or major organ resection between those who received or did not receive neoadjuvant chemotherapy. Operative time was significantly shorter in those who did not receive neoadjuvant chemotherapy. Major complications and length of hospital stay were similar between the groups. The median actuarial overall survival calculated from the date of initial therapeutic intervention was not different in those treated with or without neoadjuvant therapy. CONCLUSIONS: Neoadjuvant chemotherapy has marked clinical activity in patients with PM from high-grade appendiceal adenocarcinoma and does not adversely affect operative outcomes. These data support conducting a prospective clinical trial to define the role of neoadjuvant chemotherapy in this clinical setting.

Assessment of clinical benefit and quality of life in patients undergoing cytoreduction and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for management of peritoneal metastases.

Peritoneal metastasis is a significant clinical challenge; life expectancy following diagnosis is usually very short. Surgical cytoreduction with HIPEC is being used with increasing frequency in selected patients; most outcome data have shown that prolonged median survivals can be observed in selected patients. This review summarizes the published data related to outcome and quality of life after cytoreduction and HIPEC to provide insights into its use in patients with peritoneal carcinomatosis.

Clinical and demographic characteristics associated with the receipt of chemotherapy treatment among 7951 elderly metastatic colon cancer patients.

Among older individuals diagnosed with metastatic colon cancer (mCC) there is limited evidence available that describes the characteristics associated with advancing to second- and subsequent lines of treatment with chemotherapy/biologics. Our objective was to describe the trends and lines of treatment received among elderly mCC patients. Elderly beneficiaries diagnosed with mCC from 2003 to 2007 were identified in the Surveillance, Epidemiology and End Results (SEER)-Medicare dataset. Beneficiaries were followed up until death or censoring. Treatment lines were classified in combinations of chemotherapies and biologics. Modified Poisson regression was used to predict receipt of lines of treatment. Analyses controlled for age, race/ethnicity, gender, marital status, state buy-in during diagnosis year, SEER-registry site, Charlson comorbidity index (CCI), poor performance indicators, surgery of primary site, and surgery of regional/distal sites. Among 7951 Medicare beneficiaries identified with mCC, 3266 initiated therapy. Of these, 1440 advanced to second-line treatment. Of these, 274 advanced to a subsequent-line treatment. Surgeries of the primary tumor site and of the regional/distal sites and marital status were the most significant variables associated with advancing through second- and subsequent-line treatments. Greater than 80 years of age, African American race, SEER-registry area, less than 6 months state buy-in assistance in mCC diagnosis year, and having poor performance indicators were inversely associated with receipt of second- or subsequent-line treatments. Among elderly individuals diagnosed with mCC, we identified demographic, clinical, and regional factors associated with receipt of second- and subsequent-line chemotherapy/biologics. Additional research is warranted to understand the role of physician versus patient preferences as well as geographic differences explaining why patients advance through lines of chemotherapy.

Inappropriate use of the faecal occult blood test outside of the National Health Service colorectal cancer screening programme.

OBJECTIVE: The faecal occult blood test (FOBT) is the screening test validated for use in the National Health Service (NHS) Bowel Cancer Screening Programme (BCSP) after trials demonstrated a 16% reduction in colorectal cancer-specific mortality. FOBT is not validated for use outside the BCSP. The aim was to investigate the number of FOBTs performed outside of the NHS BCSP at a single centre. METHODS: All FOBTs performed over 1 year were identified. Basic patient demographics, requesting physician and FOBT results were obtained. Referrals and outcomes of the investigation following the FOBT were collected. RESULTS: A total of 758 FOBTs were requested in 701 patients (352 female; median age 69; range 16-99). The majority (91%) were requested by general practitioners. A total of 515 out of 758 tests (68%) were performed in patients outside the NHS BCSP age range. Thirty-seven out of 86 positive FOBTs were investigated, diagnosing four rectal cancers and two polyps. Forty-nine out of 87 patients with a positive FOBT were not investigated further by the requesting physician or the test repeated. Of the remaining 672 FOBTs, 615 were negative and 57 were either incomplete or unsuitable for analysis. A total of 111 patients (18%) were referred to hospital and 105 of these had FOBT performed as part of the referral process. CONCLUSION: Our study demonstrates significant misuse of the FOBT outside the NHS BCSP. Inappropriate use leads to false positives and exposes patients to unnecessary risk. False negatives provide reassurance to patients who may have symptoms that should be investigated. The FOBT should not be available to physicians in either primary or secondary care and be restricted to NHS BCSP.

Impact of venous thromboembolism on mortality of elderly Medicare patients with stage III colon cancer.

BACKGROUND: The improvement in survival rates for patients with colon cancer has shifted the focus from examining cancer-specific mortality to exploring all-cause mortality. Adverse events such as venous thromboembolism (VTE) affect overall survival times and the net clinical benefit of cancer management strategies. METHODS: This retrospective study used Surveillance, Epidemiology and End Results (SEER) Medicare data to examine VTE incidence and mortality rates for elderly patients with stage III colon cancer who were diagnosed in 2004 or 2005 and followed through 2007. The impact of VTE on mortality was estimated using multivariable Cox proportional hazards regression. RESULTS: In all, 20.7% of 4,985 elderly patients with stage III colon cancer had clinically diagnosed VTE following diagnosis. All-cause mortality risk was higher for patients with a VTE diagnosis (hazard ratio [HR]: 1.15, 95% confidence interval [CI]: 1.04-1.27), greater comorbidity burden, more advanced tumor depth and nodal involvement within stage III, advanced age, and male sex; the risk was lower for patients treated with chemotherapy. VTE was associated with higher mortality hazards (HR: 1.41, 95% CI: 1.21-1.64) for patients treated with adjuvant chemotherapy but not for untreated patients. CONCLUSIONS: A new diagnosis of VTE significantly reduced survival rates for elderly patients with stage III colon cancer and further reduced survival rates for patients treated with chemotherapy. Improved prevention and management of VTE for elderly patients with stage III colon cancer who are at risk for VTE is warranted, particularly for patients treated with chemotherapy.

Comparative and cost-effectiveness of oxaliplatin-based or irinotecan-based regimens compared with 5-fluorouracil/leucovorin alone among US elderly stage IV colon cancer patients.

BACKGROUND: Clinical trials have shown a statistically significant disease-free survival benefit of oxaliplatin-based or irinotecan-based combination regimens for stage IV colon cancer. Less is known regarding the comparative effectiveness and cost-effectiveness of these agents among elderly patients. Whether the benefits of these agents justify the additional costs for elderly Medicare recipients is particularly policy relevant after US health care reform. METHODS: A cost-effectiveness analysis of oxaliplatin-based or irinotecan-based combination therapy versus 5-fluorouracil/leucovorin alone in elderly stage IV colon cancer patients was performed from a US Medicare perspective. Survival and direct medical costs were estimated using Surveillance, Epidemiology, and End Results-Medicare data sets for patients diagnosed from 2002 to 2005 with follow-up through 2007. Incremental cost-effectiveness ratios (ICERs) were calculated as costs per life-year gained, with sensitivity analysis estimating the cost per quality-adjusted life-year (QALY). RESULTS: Median improved overall survival with 5-fluorouracil/leucovorin alone, or irinotecan-based or oxaliplatin-based combination therapy was 0.99, 1.07, and 1.47 life-years, respectively. Costs per life-year gained for oxaliplatin-based or irinotecan-based combination regimens compared with 5-fluorouracil/leucovorin alone were $78,181 and $267,938, respectively. ICERs comparing oxaliplatin-based to irinotecan-based regimens were $40,230 per life-year gained or $160,920 per QALY. CONCLUSIONS: Oxaliplatin-based or irinotecan-based combination therapy improves overall survival but also substantially increases direct medical costs compared with 5-fluorouracil/leucovorin alone when used in elderly US patients with stage IV colon cancer. Oxaliplatin-based regimens are more cost-effective than irinotecan-based regimens for treatment of elderly stage IV colon cancer patients in terms of cost per life-year gained, but not in terms of cost per QALY.

Cancer caregiving and subjective stress: a multi-site, multi-dimensional analysis.

Although research has emerged documenting the psychosocial impact of family care for cancer patients, few efforts capture the multi-dimensional nature of cancer caregiving stress, particularly among socioeconomically diverse samples. Utilizing data collected from cancer caregivers at a non-urban, Southern US site and an inner-city, Northeastern US site (N=233), the present study identified predictors of multiple dimensions of caregivers' subjective stress (i.e. emotional appraisals of care demands). Various indicators representing the sociodemographic context of care, cancer care demands, and psychosocial resources were found to exacerbate or buffer caregivers from feelings of exhaustion, role entrapment, and loss of intimacy with the cancer patient. The multivariate regression model also emphasized the diffuse yet potent role care recipient mood problems and caregiver mastery/optimism have on multiple dimensions of subjective stress. The findings offer a number of recommendations for future research and practice focused on informal cancer care.