Obtention of viable cell suspensions from breast cancer tumor biopsies for 3D chromatin conformation and single-cell transcriptome analysis.

Molecular and cellular characterization of tumors is essential due to the complex and heterogeneous nature of cancer. In recent decades, many bioinformatic tools and experimental techniques have been developed to achieve personalized characterization of tumors. However, sample handling continues to be a major challenge as limitations such as prior treatments before sample acquisition, the amount of tissue obtained, transportation, or the inability to process fresh samples pose a hurdle for experimental strategies that require viable cell suspensions. Here, we present an optimized protocol that allows the recovery of highly viable cell suspensions from breast cancer primary tumor biopsies. Using these cell suspensions we have successfully characterized genome architecture through Hi-C. Also, we have evaluated single-cell gene expression and the tumor cellular microenvironment through single-cell RNAseq. Both technologies are key in the detailed and personalized molecular characterization of tumor samples. The protocol described here is a cost-effective alternative to obtain viable cell suspensions from biopsies simply and efficiently.

Prevalence and spectrum of germline pathogenic variants in cancer susceptibility genes among mexican patients with exocrine pancreatic cancer.

BACKGROUND: Although universal germline genetic testing is recommended for patients with exocrine pancreatic cancer (PC), access to genetic testing remains limited in low- and middle-income countries. This study aims to narrow the gap in our understanding of the spectrum of germline pathogenic and likely pathogenic variants (PVs) in cancer susceptibility genes in the Mexican population. METHODS: The landscape of PVs in cancer susceptibility genes was identified by next-generation sequencing multigene panel assays among patients with PC who were enrolled in the Clinical Cancer Genomics Community Research Network prospective registry in Mexico City. RESULTS: From August 2019 to April 2023, 137 patients underwent genetic testing. The median age at diagnosis was 60 years (range 36-85), 58.4 % were women, and 38.7 % were metastatic at diagnosis. The frequency of germline PVs was 16 % (n = 22): ATM 36.4 % (n = 8), CDKN2A/p16INK4A 27.3 % (n = 6), BRCA2 9.1 % (n = 2), PALB2 9.1 % (n = 2), CHEK2 9.1 % (n = 2), TP53 4.5 % (n = 1), and NF1 4.5 % (n = 1). Additionally, 2 carriers of monoallelic germline variants in MUTYH were identified. No significant differences were observed between carriers and non-carriers in terms of family history of pancreatic cancer. CONCLUSIONS: We identified a significant frequency of actionable germline PVs in Mexicans with PC, wherein the majority were in a broad spectrum of genes associated with the homologous recombination DNA repair mechanism. Most pancreatic cancer associated PVs were detected in non-BRCA genes, so our findings support the recommendation of multigene panel testing for genetic cancer risk assessment of Mexican individuals with PC.

Time toxicity among older patients with cancer treated with palliative systemic therapy.

PURPOSE: The time toxicity of anticancer therapy, defined as days spent with healthcare contact during treatment, represents a critical but understudied outcome. This study aims to quantify time toxicity among older patients with cancer receiving palliative systemic treatment. METHODS: All patients aged ≥ 65 years with metastatic cancer receiving cytotoxic chemotherapy, immunotherapy, or targeted therapy at a single center in Mexico were selected from a prospective patient navigation cohort. Patients completed a baseline assessment, including the G8 screening and quality of life measures. Physical healthcare contact days within the first 6 months were extracted from medical records and divided by days alive during the same period. Beta regression models were used to identify predictors of time toxicity. RESULTS: We identified 158 older patients (median age 71 years); 86% received cytotoxic chemotherapy. Seventy-three percent had an impaired G8 score and were considered vulnerable/frail. Six-month overall survival was 74%. Within the first 6 months, patients spent a mean of 21% (95% confidence interval (CI) 19-23%) of days with healthcare contact. Concurrent radiotherapy (odds ratio (OR) 1.55; 95%CI 1.21-1.97), cytotoxic chemotherapy versus targeted therapy (OR 1.64; 95%CI 1.13-2.37), and an impaired G8 (OR 1.27; 95%CI 1.01-1.60) were associated with increased time toxicity. CONCLUSION: Older adults with metastatic cancer spend 1 in 5 days with healthcare contact during treatment, with a higher burden of time toxicity for patients receiving radiotherapy or cytotoxic chemotherapy and those with potential frailty. These findings underscore the importance of informing patients about their expected healthcare contact days within the context of a limited life expectancy.

Lynch syndrome in Mexican-Mestizo families: Genotype, phenotypes, and challenges in cascade testing among relatives at risk.

Lynch syndrome (LS) is the most frequent cancer predisposition syndrome affecting the colon and rectum. A pathogenic variant (PV) disrupting one of the mismatch repair (MMR) genes is responsible for the disease. The spectrum of tumors in LS is heterogeneous and includes cancer of the colon and rectum (CRC), endometrium, ovaries, stomach, small bowel, urinary tract, bladder, pancreas, and skin. Knowledge of the phenotypic variation of patients with LS, the type and frequency of PVs, and cascade testing studies in the Latin American population is limited. The present study aims to recognize the PVs in MMR genes, describe the phenotype in Mexican-Mestizo patients and their relatives, and identify the acceptance rate of cascade testing of relatives at risk. We included 40 carriers of a MMR gene PV and 142 relatives that developed a LS-related neoplasm. Patients' clinical data, number, and type of malignancies were obtained from their medical records. Amsterdam I-II, Bethesda criteria, and PREMM5® predictive model score were estimated. Available immunohistochemistry (IHC) reports were analyzed. Relatives at risk were determined from index cases pedigrees. The distribution of MMR gene mutations among 40 probands was: MLH1 (67.5 %), MSH2 (22.5 %), MSH6 (7.5 %), and PMS2 (2.5 %). Out of the 182 LS cases, 58 % exhibited the LS phenotype before age 50. The most common tumor was CRC, followed by endometrial cancer in women and gastric cancer in males. We found a 90.0 % concordance between the IHC and germline PV. The most frequent PV in our sample was MLH1 c.676C > T, occurring in 1/6 index cases. All probands disclosed their molecular test result to their family. Out of the 451 asymptomatic relatives at risk, 28.2 % underwent germline testing. Our results highlight the importance of conducting germline genetic studies in LS since it allows the establishment of appropriate cancer screening, risk-reducing measures, and genetic cascade testing among relatives at risk. Interestingly, we observed a significantly higher prevalence of the c.676C > T variant in MLH1, probably a singular characteristic of the Mexican-Mestizo population. New strategies to facilitate accurate communication between index cases and relatives should be implemented to improve the cascade testing acceptance rate.

Addressing the Historic Challenges of BRCA1 and BRCA2 Variant Curation and the Need for More Diverse Representation.

Advancements in variant curation challenges: minority representation and incomplete data reporting.

Multicenter Study on the Frequency of Low Bone Mineral Density in Young Women With Breast Cancer and Associated Factors.

INTRODUCTION: Young women with breast cancer (BC) may experience bone mineral density (BMD) loss secondary to cancer treatment effects on estrogen levels. Studies assessing BMD in BC patients have had a limited representation of young women. This multicenter retrospective study analyzed the frequency of low BMD and associated factors in this age group. METHODS: Women diagnosed with stage 0-III BC at ≤40 years, treated with chemotherapy and/or endocrine therapy between 2010 and 2020 at 5 Mexican BC referral centers were eligible. Demographic, clinical and treatment data were collected, as well as bone dual-energy X-ray absorptiometry (DEXA) results. Low BMD was defined as lumbar or femoral neck T-score < -1.0 or Z-score ≤ -2.0. RESULTS: A total of 1259 patients were included; median age at diagnosis was 36 years (21-40). Overall, 93% received chemotherapy and 65% endocrine therapy (tamoxifen was received at some point by 61%, aromatase inhibitors by 17%, and GnRH agonists/bilateral oophorectomy by 21%). DEXA scans were documented in 254 (20%), of which 163 (64%; 95% confidence interval [CI] 58%-70%) had a low BMD report. Low BMD was associated with receiving aromatase inhibitors (Odds ratio [OR] 1.92; 95% CI 1.13-3.24), and GnRH agonists/bilateral oophorectomy (OR 2.25; 95% CI 1.21-4.21). CONCLUSION: The suboptimal frequency of BMD monitoring observed displays an alarming disregard for bone health in young patients. Thus, a high proportion of women with low BMD are potentially being missed and precluded from the opportunity to receive timely interventions. Particular focus should be put on BMD monitoring among patients treated with aromatase inhibitors, GnRH agonists or bilateral oophorectomy.

Selection of Germline Genetic Testing Panels in Patients With Cancer: ASCO Guideline.

PURPOSE: To guide use of multigene panels for germline genetic testing for patients with cancer. METHODS: An ASCO Expert Panel convened to develop recommendations on the basis of a systematic review of guidelines, consensus statements, and studies of germline and somatic genetic testing. RESULTS: Fifty-two guidelines and consensus statements met eligibility criteria for the primary search; 14 studies were identified for Clinical Question 4. RECOMMENDATIONS: Patients should have a family history taken and recorded that includes details of cancers in first- and second-degree relatives and the patient's ethnicity. When more than one gene is relevant based on personal and/or family history, multigene panel testing should be offered. When considering what genes to include in the panel, the minimal panel should include the more strongly recommended genes from Table 1 and may include those less strongly recommended. A broader panel may be ordered when the potential benefits are clearly identified, and the potential harms from uncertain results should be mitigated. Patients who meet criteria for germline genetic testing should be offered germline testing regardless of results from tumor testing. Patients who would not normally be offered germline genetic testing based on personal and/or family history criteria but who have a pathogenic or likely pathogenic variant identified by tumor testing in a gene listed in Table 2 under the outlined circumstances should be offered germline testing.Additional information is available at www.asco.org/molecular-testing-and-biomarkers-guidelines.

Supportive care needs among older Mexican adults with metastatic cancer.

INTRODUCTION: Supportive care needs may vary according to age. The purpose of this research is to describe and compare supportive care needs between older adults with metastatic cancer (age ≥ 65 years) and their younger counterparts. MATERIALS AND METHODS: We conducted a retrospective secondary analysis of a cohort of patients with newly diagnosed metastatic solid tumors. Supportive care needs were assessed at baseline and at a three-month follow-up. Patients were divided into two groups (aged ≥65/<65 years). Differences in clinical characteristics and supportive care needs were compared utilizing descriptive statistics. Multivariate logistic regression models were employed to identify patient characteristics associated with specific supportive care needs. RESULTS: Between 2018 and 2022, 375 patients were enrolled. Median age was 66 years (interquartile range 19-94). At baseline, older adults had a higher number of supportive care needs (4.8 vs. 4.2, p = 0.01) and were at higher risk of malnutrition (75 vs. 65%, p = 0.05). Increasing age (odds ratio [OR] 1.02 (95% confidence interval [CI] 1.0-1.04, p = 0.03) and an estimated life expectancy <6 months (OR 3.0, 95%CI 1.5-6.1; p < 0.01) were associated with higher odds of malnutrition, while a higher educational level was associated with decreased odds (OR 0.68, 95%CI 0.5-0.8; p < 0.01). At three-month follow-up, older adults still had a higher number of supportive care needs (3.8 vs.2.6, p < 0.01) and were more likely to have fatigue (62 vs. 47%, p = 0.02). An estimated life expectancy of <6 months was associated with increased odds of fatigue (OR 3.0, 95%CI 1.5-6.3; p < 0.01). DISCUSSION: Older adults reported significantly more supportive care needs, particularly risk of malnutrition and fatigue. This information can help in the creation of supportive care services tailored to the needs of older individuals.

Uptake of Risk-Reducing Measures, Cascade Testing, and Related Challenges Among Carriers of Breast Cancer-Associated Germline Pathogenic Variants in Mexico.

PURPOSE: Genetic cancer risk assessment (GCRA) provides pathogenic variant (PV) carriers with the invaluable opportunity to undertake timely cancer risk-reducing (RR) measures and initiate cascade testing (CT). This study describes the uptake of these strategies and the related barriers among breast cancer-associated germline PV carriers in Mexico. METHODS: Carriers who were at least 6 months after disclosure of genetic test results at two GCRA referral centers were invited to answer a survey assessing sociodemographic characteristics, awareness of their carrier status and its implications, uptake of RR measures according to international guidelines by PV, CT initiation, and associated challenges. RESULTS: Of the eligible carriers, 246/384 (64%) answered the survey (median age: 44 years). Most were female (88%), married/in domestic partnership (66%), and had personal breast/ovarian cancer history (61%). PVs included BRCA1/2 (75%), CHEK2 (10%), PALB2 (5%), ATM (5%), NF1 (2%), RAD51C (2%), PTEN (1%), and TP53 (1%). Most (87%) participants were aware of their carrier status. When recommended, 37% underwent RR bilateral mastectomy, 48% RR oophorectomy, 70% annual mammogram, and 20% breast magnetic resonance imaging. Challenges hindering the uptake of RR measures included financial limitations (67%), lack of recommendation by their physician (35%), and fear (24%). Nearly all (98%) claimed sharing their results with their relatives. CT was initiated in 63% of families and was associated with carriers being married/in domestic partnership (P = .04) and believing GCRA was useful (P < .001). CONCLUSION: Despite the resource-constrained setting, relevant rates of RR measures and CT were observed. Targeted interventions to reduce out-of-pocket expenses and improve patient-physician communication and patients' understanding on carrier status are warranted to enhance the overall benefit of GCRA and ultimately improve the provision of patient-centered care to both carriers and their at-risk relatives.

Locoregional therapy containing surgery in metastatic breast cancer: Systematic review and meta-analysis.

INTRODUCTION: The role of locoregional therapy (LRT) containing surgery and systematic therapy in metastatic breast cancer patients remains controversial. This study investigated the effect of LRT in patients who were initially diagnosed with metastatic breast cancer (MBC) on overall survival (OS), locoregional progression-free survival (PFS), and distant systemic PFS. METHODS: The related keywords were searched in MEDLINE/PubMed, SCOPUS, and Web of Science databases up to August 15th, 2022. Hazard ratios (HR) with 95% confidence intervals (CIs) were pooled by the random-effects model. RESULTS: Seven articles with 1626 participants compared LRT with only systemic therapy (ST) for patients with de novo MBC. LRT did not improve (p = 0.28) OS compared to ST (HR: 0.83, 95% CI: 0.60, 1.16). LRT significantly improved locoregional PFS outcomes compared to ST (HR: 0.31, 95% CI: 0.15, 0.60, p = 0.001). LRT significantly (p = 0.001) improved OS in patients with solitary bone metastases (HR: 0.48; 95% CI: 0.35-0.67). CONCLUSION: LRT improves locoregional PFS. Furthermore, LRT improves OS in patients with solitary bone metastases.

Germline DNA Repair Genes Pathogenic Variants Among Mexican Patients With Prostate Cancer.

BACKGROUND: Early identification of germline mutation carriers may be relevant for the optimal management of prostate cancer and to inform cancer risk in relatives. However, population minorities have limited access to genetic testing. The aim of this study was to describe the frequency of DNA repair gene pathogenic variants (PVs) among Mexican men with prostate cancer referred for Genomic Cancer Risk Assessment and testing. METHODS: Patients diagnosed with prostate cancer who meet criteria for genetic testing and enrolled in the Clinical Cancer Genomics Community Research Network at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in Mexico City were included. Descriptive statistics were performed using frequency and proportions for categorical variables and median and range for quantitative variables. X2 and t test were used for group comparisons. RESULTS: A total of 199 men were enrolled, median age at diagnosis was 66 (range 44-88) years; 45% were de novo metastatic and 44% were high- very high and 10% were intermediate risk group. Four (2%) had a pathogenic germline variant; one each of the following genes: ATM, CHEK2, BRIP1, and MUTYH (all monoallelic). Younger men at diagnosis were more likely to carry a PV than older age at diagnosis (56.7 vs. 66.4 years, P = .01). CONCLUSION: Our results showed a low prevalence of known prostate cancer associated PVs and no BRCA PVs in Mexican men with prostate cancer. This suggests that the genetic and/or epidemiologic risk factors for prostate cancer are not well characterized in this specific population.

Tamoxifen use and risk of endometrial cancer in breast cancer patients: A systematic review and dose-response meta-analysis.

BACKGROUND: Worse prognosis of endometrial cancers (EC) in tamoxifen-treated women compared to non-tamoxifen-treated women been proposed. The relationship between tamoxifen treatment of breast cancer (BC) and the risk of EC is controversial and there is no agreement between publication results on this issue (the answer to all comments provided in the page 2 of manuscript). The aim of this study is investigation the association between tamoxifen treatment and the risk of EC in patients with BC. METHODS AND RESULTS: We conducted a comprehensive search with related keywords in MEDLINE/PubMed, SCOPUS, and Web of Science databases until April 16, 2022. Random-effects model (DerSimonian and Laird) was used to pool risk ratios (RRs) with 95% confidence intervals (CIs) of EC. Dose, cumulative dose, and duration-response analysis were performed in linear and non-linear states. Twenty-six studies reported a relation between tamoxifen treatment and risk of EC in patients with BC. Results showed a direct relationship between tamoxifen use and EC (RR: 2.03, 95% CI: 1.68-2.45; I2:76%). By increase the age of participants, the risk of EC was decrease (coef = -.0206), although this was not statistically significant (p = .37). Linear dose-response model indicated a direct significant association between dose and duration use of tamoxifen and EC (dose: exe(b) = 1.019, p = .001; duration: exe(b) = 1.014, p = .001). Non-linear dose-response analysis confirmed linear analysis. CONCLUSION: This study highlights that tamoxifen use is a significant risk factor related to the incidence of EC in patients with BC.

Real-world data in patients with BRCA mutated breast cancer treated with poly (ADP-ribose) polymerase inhibitors.

Breast cancer is the most common type of cancer globally. Hereditary breast cancer accounts for 10% of new cases and 4%-5% of cases are associated to pathogenic variants in BRCA1 or BRCA2 genes. In recent years, poly-adenosine-diphosphate-ribose polymerase inhibitors (PARPi) olaparib and talazoparib have been approved for patients with BRCA-associated, HER2 -negative breast cancer. These drugs have shown positive results in the early and advanced setting with a favourable toxicity profile based on the OlympiAD, OlympiA and EMBRACA phase 3 trials. However, patients included in these randomised trials are highly selected, making toxicity and efficacy in patients encountered in routine clinical care a concern. Since the approval of olaparib and talazoparib for advanced human epidermal growth factor receptor 2-negative (HER2-negative) breast cancer, several phase IIIb-IV trials, expanded access cohorts, and retrospective cohorts have provided information on the efficacy and tolerability of these treatments in patient subgroups underrepresented in the registration trials, such as older adults, patients with poor performance status, and heavily pretreated patients. The aim of this review is to present a critical review of the information regarding the use of PARPi in real-world breast cancer patients.

End-of-Life Care and Advanced Directives in Hispanic/Latinx Patients: Challenges and Solutions for the Practicing Oncologist.

Advanced end-of-life care (EOL) comprises a group of strategies to provide comfort to patients at the end of life. These are associated with better quality of life, better satisfaction, and a lower rate of hospitalizations and aggressive medical treatment. Advanced EOL care, including advanced directives completion and hospice enrollment, is suboptimal among Hispanic/Latinx patients with cancer due to personal, socio-cultural, financial, and health system-related barriers, as well as due to a lack of studies specifically designed for this population. In addition, the extrapolation of programs that increase participation in EOL for non-white Hispanics may not work appropriately for Hispanic/Latinx patients and lead to overall lower satisfaction and enrollment in EOL care. This review will provide the practicing oncologist with the tools to address EOL in the Hispanic/Latinx population. Some promising strategies to address the EOL care disparities in Latinx/Hispanic patients have been culturally tailored patient navigation programs, geriatric assessment-guided multidisciplinary interventions, counseling sessions, and educational interventions. Through these strategies, we encourage oncologists to take advantage of every clinical setting to discuss EOL care. Treating physicians can engage family members in caring for their loved ones while practicing cultural humility and respecting cultural preferences, incorporating policies to foster treatment for the underserved migrant population, and providing patients with validated Spanish language tools.

Germline Pathogenic Variant Prevalence Among Latin American and US Hispanic Individuals Undergoing Testing for Hereditary Breast and Ovarian Cancer: A Cross-Sectional Study.

PURPOSE: To report on pathogenic germline variants detected among individuals undergoing genetic testing for hereditary breast and/or ovarian cancer (HBOC) from Latin America and compare them with self-reported Hispanic individuals from the United States. METHODS: In this cross-sectional study, unrelated individuals with a personal/family history suggestive of HBOC who received clinician-ordered germline multigene sequencing were grouped according to the location of the ordering physician: group A, Mexico, Central America, and the Caribbean; group B, South America; and group C, United States with individuals who self-reported Hispanic ethnicity. Relatives who underwent cascade testing were analyzed separately. RESULTS: Among 24,075 unrelated probands across all regions, most were female (94.9%) and reported a personal history suggestive of HBOC (range, 65.0%-80.6%); the mean age at testing was 49.1 ± 13.1 years. The average number of genes analyzed per patient was highest in group A (A 63 ± 28, B 56 ± 29, and C 40 ± 28). Between 9.1% and 18.7% of patients had pathogenic germline variants in HBOC genes (highest yield in group A), with the majority associated with high HBOC risk. Compared with US Hispanics individuals the overall yield was significantly higher in both Latin American regions (A v C P = 1.64×10-9, B v C P < 2.2×10-16). Rates of variants of uncertain significance were similar across all three regions (33.7%-42.6%). Cascade testing uptake was low in all regions (A 6.6%, B 4.5%, and C 1.9%). CONCLUSION: This study highlights the importance of multigene panel testing in Latin American individuals with newly diagnosed or history of HBOC, who can benefit from medical management changes including targeted therapies, eligibility to clinical trials, risk-reducing surgeries, surveillance and prevention of secondary malignancy, and genetic counseling and subsequent cascade testing of at-risk relatives.

MASCC/ISOO expert opinion on the management of oral problems in patients with advanced cancer.

PURPOSE: The Palliative Care Study Group in conjunction with the Oral Care Study Group of the Multinational Association for Supportive Care in Cancer (MASCC) formed a sub-group to develop evidence-based guidance on the management of common oral problems in patients with advanced cancer. METHODS: This guidance was developed in accordance with the MASCC Guidelines Policy. A search strategy for Medline was developed, and the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials were explored for relevant reviews and trials, respectively. Guidance was categorised by the level of evidence, and "category of guideline" (i.e., "recommendation", "suggestion" or "no guideline possible"). RESULTS: Twelve generic suggestions (level of evidence - 5), three problem-specific recommendations and 14 problem-specific suggestions were generated. The generic suggestions relate to oral hygiene measures, assessment of problems, principles of management, re-assessment of problems and the role of dental/oral medicine professionals. CONCLUSIONS: This guidance provides a framework for the management of common oral problems in patients with advanced cancer, although every patient requires individualised management.

Germline pathogenic variants in Mexican patients with hereditary triple-negative breast cancer.

OBJECTIVE: Describe the prevalence of breast cancer (BC)- associated germline pathogenic variants (PVs) among Mexican patients with triple-negative BC (TNBC). MATERIALS AND METHODS: The spectrum of PVs identified among patients with TNBC who were enrolled in a prospective registry and underwent genetic testing was analyzed. RESULTS: Of 387 patients with invasive TNBC and a median age at diagnosis of 39 years (range 21-72), 113 (29%) were carriers of PVs in BC-susceptibility genes: BRCA1 (79%), BRCA2 (15%), and other (6%: ATM, BRIP1, PALB2, PTEN, RAD51C, and TP53). PV carriers were younger at BC diagnosis (37 vs. 40 years, p=0.004) than non-carriers. CONCLUSION: A large proportion of TNBC in Mexican patients is associated with germline PVs, the vast majority in BRCA. The incremental yield of PVs in other BC-susceptibility genes was modest, and a stepwise approach starting with BRCA testing may be justified if it is more cost-effective than multigene panel testing.

Financial Toxicity Among Older Mexican Adults With Cancer and Their Families: A Mixed-Methods Study.

PURPOSE: The financial toxicity (FT) of cancer is common among older adults in high-income countries, but little is known about the financial hardships faced by older patients with cancer living in developing countries. The aim of this study was to explore the financial burden of cancer among older Mexican adults and their relatives, as well as factors that might mitigate such burden. METHODS: This mixed-methods study included patients age 65 years and older with the 10 most common malignancies in Mexico and 3-24 months from diagnosis at two cancer centers in Mexico City and their relatives. For the quantitative component, patients and relatives answered the Spanish version of the Consumer Financial Protection Bureau Financial Well-Being Scale. Patients completed the Comprehensive Score for Financial Toxicity-Functional Assessment of Chronic Illness Therapy (COST-FACIT) scale and a 3-month, self-reported cost diary. For the qualitative component, focused interviews were used to explore the individual experiences of patients and their relatives. RESULTS: Ninety-six patients and their relatives were included, of whom 45% had stage IV disease. On the COST-FACIT scale, 9% reported no FT, 52% mild FT, 39% moderate FT, and 0% severe FT. The mean Consumer Financial Protection Bureau Financial Well-Being Scale score was 45.2, with 78% reporting poor financial well-being (score ≤ 50). On cost diaries, most expenses were associated with purchasing medications, including chemotherapy. Focused interviews showed that most patients and relatives had to acquire debt to face costs of cancer care. CONCLUSION: A high proportion of Mexican older adults with cancer reported FT and poor financial well-being. Understanding experiences associated with FT and strategies to mitigate it represents an essential first step to design public policies aimed at protecting older adults with cancer and their families from catastrophic spending.