Assessing frailty in older Indian patients before cancer treatment: Comparative analysis of three scales and their implications for overall survival

INTRODUCTION

Frailty, characterized by ageing-related vulnerability, influences outcomes in older adults. Our study aimed to investigate the relationship between frailty and clinical outcomes in older Indian patients with cancer.

MATERIALS AND METHODS

Our observational single-centre study, conducted at Tata Memorial Hospital from February 2020 to July 2022, enrolled participants aged 60 years and above with cancer. Frailty was assessed using the Clinical Frailty Scale (CFS), G8, and Vulnerable Elders Survey (VES)-13. The primary objective was to explore the correlation between baseline frailty and overall survival. Statistical analyses include Kaplan-Meier, Cox proportional hazards, and Harrell's C test.

RESULTS

A total of 1,177 patients (median age 68, 76.9% male) were evaluated in the geriatric oncology clinic. Common malignancies included lung (40.0%), gastrointestinal (35.8%), urological (11.9%), and head and neck (9.0%), with 56.5% having metastatic disease. Using CFS, G8, and VES-13 scales, 28.5%, 86.4%, and 38.0% were identified as frail, respectively. Median follow-up was 11.6 months, with 43.3% deaths. Patients fit on CFS (CFS 1-2) had a median survival of 28.02 months, pre-frail (CFS 3-4) 13.24 months, and frail (CFS ≥5) 7.79 months (p < 0.001). Abnormal G8 (≤14) and VES-13 (≥3) were associated with significantly lower median survival (p < 0.001). Multivariate analysis confirmed CFS's predictive power for mortality (p < 0.001), with hazard ratios [HRs] for pre-frail at 1.61(95% confidence interval [CI] 1.25 to 2.06) and frail at 2.31 (95%CI 1.74 to 3.05). G8 ≤ 14 had HR 2.00 (95%CI 1.42 to 2.83), and abnormal VES-13 had HR 1.36 (95%CI 1.11-1.67). In the likelihood ratio test, CFS significantly improved the model fit (p < 0.001). Harrell's C index for survival prediction was 0.62 for CFS, 0.54 for G8, and 0.58 for VES-13.

DISCUSSION

In conclusion, our study highlights varying frailty prevalence and prognostic implications in older Indian patients with cancer, emphasizing the need for personalized care in oncology for this aging population. We would recommend using CFS as a tool to screen for frailty for older Indian patients with cancer.

Performance of potentially inappropriate medications assessment tools in older Indian patients with cancer

BACKGROUND

Polypharmacy and potentially inappropriate medication (PIM) use are common problems in older adults. Safe prescription practices are a necessity. The tools employed for the identification of PIM sometimes do not concur with each other.

METHODS

A retrospective analysis of patients ≥60 years who visited the Geriatric Oncology Clinic of the Tata Memorial Hospital, Mumbai, India from 2018 to 2021 was performed. Beer's-2015, STOPP/START criteria v2, PRISCUS-2010, Fit fOR The Aged (FORTA)-2018, and the EU(7)-PIM list-2015 were the tools used to assess PIM. Every patient was assigned a standardized PIM value (SPV) for each scale, which represented the ratio of the number of PIMs identified by a given scale to the total number of medications taken. The median SPV of all five tools was considered the reference standard for each patient. Bland-Altman plots were utilized to determine agreement between each scale and the reference. Association between baseline variables and PIM use was determined using multiple logistic regression analysis.

RESULTS

Of the 467 patients included in this analysis, there were 372 (79.66%) males and 95 (20.34%) females with an average age of 70 ± 5.91 years. The EU(7)-PIM list was found to have the highest level of agreement given by a bias estimate of 0.010, the lowest compared to any other scale. The 95% CI of the bias was in the narrow range of -0.001 to 0.022, demonstrating the precision of the estimate. In comparison, the bias (95%) CI of Beer's criteria, STOPP/START criteria, PRISCUS list, and FORTA list were -0.039 (-0.053 to -0.025), 0.076 (0.060 to 0.092), 0.035 (0.021 to 0.049), and -0.148 (-0.165 to -0.130), respectively. Patients on polypharmacy had significantly higher PIM use compared to those without (OR = 1.47 (1.33-1.63), p = <0.001).

CONCLUSIONS

The EU(7)-PIM list was found to have the least bias and hence can be considered the most reliable among all other tools studied.

Correlation of the Geriatric Assessment with Overall Survival in Older Patients with Cancer

AIMS

Global guidelines recommend that all older patients with cancer receiving chemotherapy should undergo a geriatric assessment. However, utilisation of the geriatric assessment is often constrained by its time-intensive nature, which limits its adoption in settings with limited resources and high demand. There is a lack of evidence correlating the results of the geriatric assessment with survival from the Indian subcontinent. Therefore, the aims of the present study were to assess the impact of the geriatric assessment on survival in older Indian patients with cancer and to identify the factors associated with survival in these older patients.

MATERIALS AND METHODS

This was an observational study, conducted in the geriatric oncology clinic of the Tata Memorial Hospital (Mumbai, India). Patients aged 60 years and older with cancer who underwent a geriatric assessment were enrolled. We assessed the non-oncological geriatric domains of function and falls, nutrition, comorbidities, cognition, psychology, social support and medications. Patients exhibiting impairment in two or more domains were classified as frail.

RESULTS

Between June 2018 and January 2022, we enrolled 897 patients. The median age was 69 (interquartile range 65-73) years. The common malignancies were lung (40.5%), oesophagus (31.9%) and genitourinary (12.1%); 54.6% had metastatic disease. Based on the results of the geriatric assessment, 767 (85.4%) patients were frail. The estimated median overall survival in fit patients was 24.3 (95% confidence interval 18.2-not reached) months, compared with 11.2 (10.1-12.8) months in frail patients (hazard ratio 0.54; 95% confidence interval 0.41-0.72, P < 0.001). This difference in overall survival remained significant after adjusting for age, sex, primary tumour and metastatic status (hazard ratio 0.56; 95% confidence interval 0.41-0.74, P < 0.001). In the patients with a performance status of 0 or 1 (n = 454), 365 (80.4%) were frail; the median overall survival in the performance status 0-1 group was 33.0 months (95% confidence interval 24.31-not reached) in the fit group versus 14.4 months (95% confidence interval 12.25-18.73) in the frail patients (hazard ratio 0.50; 95% confidence interval 0.34-0.74, P = 0.001). In the multivariate analysis, the geriatric assessment domains that were predictive of survival were function (hazard ratio 0.68; 95% confidence interval 0.52-0.88; P = 0.003), nutrition (hazard ratio 0.64; 95% confidence interval 0.48-0.85, P = 0.002) and cognition (hazard ratio 0.67; 95% confidence interval 0.49-0.91, P = 0.011).

DISCUSSION

The geriatric assessment is a powerful prognostic tool for survival among older Indian patients with cancer. The geriatric assessment is prognostic even in the cohort of patients thought to be the fittest, i.e. performance status 0 and 1. Our study re-emphasises the critical importance of the geriatric assessment in all older patients planned for cancer-directed therapy.

The current status of geriatric oncology in India

Geriatric oncology in India is relatively new. The number of older persons with cancer is increasing exponentially; at our institution, 34% of patients registered are 60 years and over. Apart from the Tata Memorial Hospital in Mumbai, there are currently no other Indian centers that have a dedicated geriatric oncology unit. Geriatric assessments (GAs) are done sporadically, and older patients with cancer are usually assessed and treated based on clinical judgement. Challenges to increasing the uptake of GA include a lack of training/time/interest or knowledge of the importance of the GA. Other challenges include a lack of trained personnel with expertise in geriatric oncology, and a paucity of research studies that seek to advance the outcomes in older Indian patients with cancer. We anticipate that over the next 10 years, along with the inevitable increase in the number of older persons with cancer in India, there will be a commensurate increase in the number of skilled personnel to care for them. Key goals for the future include increased research output, increased number of dedicated geriatric oncology units across the country, India-specific geriatric oncology guidelines, geriatric oncology training programs, and a focus on collaborative work across India and with global partners. In this narrative review, we provide a broad overview of the status of geriatric oncology in India, along with a description of the work done at our center. We hope to spark interest and provide inspiration to readers to consider developing geriatric oncology services in other settings.

Validation of the Onco-MPI in predicting short-term mortality in older Indian patients with cancer

INTRODUCTION

The number of older patients with cancer is increasing exponentially worldwide, and a similar trend has also been noted in India. The Multidimensional Prognostic Index (MPI) strongly correlates the presence of individual comorbidities with mortality, and the Onco-MPI prognosticates patients accurately for overall mortality. However, limited studies have evaluated this index in patient populations beyond Italy. We evaluated the performance of the Onco-MPI index in predicting mortality in older Indian patients with cancer.

MATERIALS AND METHODS

This observational study was conducted between October 2019 and November 2021 in the Geriatric Oncology Clinic at Tata Memorial Hospital in Mumbai, India. The data of patients aged ≥60 years with solid tumors who underwent a comprehensive geriatric assessment was analysed. The study's primary aim was to calculate the Onco-MPI for patients in the study and correlate it with one-year mortality.

RESULTS

A total of 576 patients aged ≥60 years were included in the study. The median age (range) of the population was 68 (60-90) years, and 429 (74.5%) were male. After a median follow-up of 19.2 months, 366 (63.7%) patients had died. The proportion of patients classified as low risk (0-0.46), moderate risk (0.47-0.63) and high risk (0.64-1.0) were 38% (219 patients), 37% (211 patients) and 25% (145 patients), respectively. There was a significant difference in one-year mortality rates between the low-risk patients compared to medium and high-risk patients (40.6% vs 53.1% vs 71.7%; p < 0.001).

DISCUSSION

The current study validates the Onco-MPI as a predictive tool for estimating short-term mortality in older Indian patients with cancer. Further prospective studies need to build on this index to obtain a score with greater discrimination in the Indian population.

Geriatric assessment as a predictor of survival among older Indian patients with cancer

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Background: ASCO guidelines recommend that geriatric assessment (GA) should be performed in all older adults with cancer. However, GA is labor- and time-intensive, hence the uptake is poor, especially in crowded resource poor-settings. There are no data correlating GA with overall survival (OS) outcomes from the Indian subcontinent. Methods: A prospective observational study in the geriatric oncology clinic of the Tata Memorial Hospital in Mumbai, India. Patients aged 60 years and above, with cancer who underwent a GA were enrolled. The domains assessed included: function (basic and instrumental activities of daily living, timed-up-and-go), nutrition (body mass index, unintentional weight loss, mini-nutritional assessment), comorbidities, cognition, psychological (depression, anxiety), social support, and medication (polypharmacy and potentially inappropriate medications). Patients with > 2 deranged GA domains were considered frail. Results: Between June 2018 and January 2022, 909 patients were enrolled. The median age was 69 (IQR, 60-88) years. Common malignancies included lung (40%), esophagus (21%) and head and neck (11%); 53% had metastatic disease. 80% had > 2 impaired domains in GA patients had vulnerabilities in a median of 3 (IQR, 0-5) domains. Median OS in fit patients based on the GA was 17.5 (95% CI, 13.9-21.0) months vs 12.1 (95% CI, 10.1-14.0) months in frail patients, (HR 0.66; 95% CI, 0.49-0.88, p = 0.005), which remained significant after adjusting for age, sex, and stage (HR, 0.71; 95% CI: 0.53-0.94, p = 0.021). In the multivariate analysis (Table), the domains that were predictive of survival were nutrition (HR: 0.65, 95% CI: 0.47-0.92, p = 0.014), cognition (HR: 0.65; 95% CI: 0.46-0.91, p = 0.012) and fatigue (HR: 0.74, 95% CI: 0.56-0.98, p = 0.038). Conclusions: In older Indian patients with cancer, GA is a powerful prognosticator of survival. In settings where a complete GA is not possible, nutrition, cognition, and fatigue should be the minimum domains assessed. Clinical trial information: CTRI/2020/04/024675. [Table: see text]

Prevalence and outcomes of frailty in older patients with cancer: A prospective study from geriatric oncology clinic

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Background: Frail older patients present with increased symptom burden, medical complexity and reduced tolerance to medical and surgical interventions. Data regarding the prevalence of frailty and its association with outcomes, such as overall survival, is limited from India. This study aimed to establish the prevalence of frailty and its association with overall survival (OS) in older patients with cancer. Methods: This was a prospective study conducted in geriatric oncology clinic of Tata memorial hospital (Mumbai India). Patients aged 60 years and above referred to the clinic were included. Frailty was identified using the Rockwoods Clinical frailty scale, and patients with a score of five or more were diagnosed as frail. Demographic details, type of cancer, stage and multi-domains geriatric assessment was done. Cancer and Ageing Research group online toxicity tool was used to assess the chemotherapy toxicity risk. A t-test or two-sample Wilcoxon rank-sum test was used to study the association between frailty status and non-categorical variables and the Pearson chi-squared test was used to measure the association between categorical variables. The Kaplan Meier survival estimation and the Cox proportional hazard model were used to perform the survival analysis. Results: Between June 2018 to January 2022, 909 patients were evaluated and 662 patients with clinical frailty score were included. The median age was 68 (60-86) years and 107 (16%) were above the age of 75 years. The most common malignancies were lung (39%), esophagus (21%) and head and neck (10%); 53% had metastatic disease. 192 (29%) were frail, and it prevalence increased with age. Frailty status was associated with poor OS (unadjusted HR: 2.512; 95% CI: 1.931-3.268). This association was significant even after adjusting for age, gender, BMI and stage of cancer (adjusted HR: 2.104; 95% CI: 1.598-2.770). Frailty was associated with comorbidities such as diabetes (32% vs 23%, p = 0.014), chronic obstructive pulmonary disease (13% vs 7%, p = 0.045) and cardiovascular disease (19% vs 12%, p = 0.017). Among the geriatric domains, frail patients had greater incidence of polypharmacy (52% vs 33%, p < 0.01), slower gait speed (53% vs 12%, p < 0.01), impaired cognition (25% vs 7%, p < 0.01), poor nutritional status (51% vs 17%, p < 0.001), depression (29% vs 8%, p < 0.01) and anxiety (14% vs 5%, p < 0.01). Conclusions: The prevalence of frailty among older cancer patients is high. It is associated with poor physical, cognitive and psychological resilience and is associated with poor overall survival. Our study supports the routine assessment of frailty in older patients with cancer to guide treatment decisions. Clinical trial information: CTRI/2020/04/024675.

Abstract P5-21-30: Retrospective review of palbociclib (Pal) efficacy and benefit from subsequent treatments following Pal progression in patients (pts) with hormone receptor positive (HR+) and HER2 negative (HER2-) metastatic breast cancer (MBC)

Background

The cyclin-dependent kinase (CDK) 4/6 inhibitor Pal is approved for HR+ HER2- MBC. However, the optimal therapy following Pal progression is unknown. Therefore we conducted this retrospective study to review Pal efficacy and summarize the practice pattern and responses to subsequent treatments post Pal progression.

Methods

We performed a chart review of pts with HR+ HER2- MBC who began Pal treatment at Washington University Siteman Cancer Center between Feb 16, 2015 and July 13, 2016 and collected information on pts demographics, diagnosis, and treatment history. Duration of therapy was used to calculate the progression free survival (PFS) for each regimen. Treatment was considered first-line if administered without any prior systemic therapy or at least 1 year from completion of adjuvant hormonal therapy (HT). Treatments received after progression on 1st line therapy or upon relapse during or within 1 year from the completion of adjuvant HT were considered second-line regimens.

Statistical analyses were performed on SAS software, version 9.4. The Kaplan-Meier method was used to generate time-to-event curves, from which median PFS was calculated. A stratified log-rank test was used for all comparisons, and the P value derived from the comparison was reported.

Results

We completed a chart review for 81 pts (78 female and 3 male; 63 Caucasian, 14 African American, and 4 other races) with HR+ HER2- MBC (68 were ER+PR+, 13 were ER+PR-) who received Pal plus letrozole (n=65) or fulvestrant (n=15) or anastrozole (n=1), with a median age of 62.0 years (range 28.1 - 85.6) at the start of Pal.

The median follow up was 20.0 months (mos) (range 10.8 – 27.9). 25 pts were still on Pal treatment. The median PFS on Pal was 19.9 mos in the first-line setting (n=20), compared to 12.1 mos and 4.4 mos in the second-line (n=14) and subsequent lines (n=47), respectively (p=0.0287). Among the 54 pts who progressed on Pal, 38 moved on to the next treatment. 20 pts received chemotherapy and 16 pts received HT or a HT combination. 2 pts received fulvestrant plus Pal upon progression on letrozole plus Pal, and treatment was still ongoing at 4 mos and 7 mos of follow up, respectively. The most common treatments post Pal were single-agent capecitabine (Cape) (n=9) and the combination of exemestane (Exe) and everolimus (Eve) (n=8). The median PFS was 4.7 mos with Cape compared to 8.4 mos with Exe and Eve (p=0.60). The median PFS was 4.7 mos for the 20 pts who received chemo, whereas the median PFS was 4.9 mos with subsequent HT (n=16) (p=0.75).

Conclusion

Pal plus letrozole or fulvestrant is effective for the treatment of HR+ HER2- MBC, with activity observed beyond the 1st and 2nd line treatment settings. The PFS of Pal observed in this single center retrospective study is consistent with that of published data. Single-agent cape or the Exe and Eve combination were common treatment choices following progression on Pal. Although the study is limited by its small sample size, the median PFS of 8.4 mos with Exe and Eve indicates its potential efficacy in the setting of Pal progression. Additional pts and followup data will be presented.

Citation Format: Xi J, Oza A, Thomas S, Naughton M, Ademuyiwa F, Weilbaecher KN, Suresh R, Bose R, Cherian MA, Hernandez-Aya L, Frith A, Peterson LL, Krishnamurthy J, Ma CX. Retrospective review of palbociclib (Pal) efficacy and benefit from subsequent treatments following Pal progression in patients (pts) with hormone receptor positive (HR+) and HER2 negative (HER2-) metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-30.

Significance of prognostic indicators in infiltrating duct carcinoma breast: Scenario in developing country

CONTEXT

Carcinoma of the breast is one of the most common malignant tumors and is the most common cause of death from cancers in females. Early diagnosis and assessing the prognosis for each patient is essential for a better therapeutic plan and management.

AIMS

To evaluate the significance of various prognostic indicators of breast carcinoma by correlating with Nottingham modification of Scarff Bloom-Richardson's grading system (NMBGS).

MATERIALS AND METHODS

Eighty four patients who underwent mastectomy for breast carcinoma at a tertiary care centre in South India over a period of 2 years have been evaluated to note the importance of the various prognostic factors correlating them with NMBGS.

STATISTICAL ANALYSIS

A Chi-square test was used to determine possible association between the various prognostic factors.

RESULTS

Eighty percent of the tumors were infiltrating ductal carcinoma (IDC), and it is seen that the larger tumor size, higher histopathological grade, increased lymphovascular invasion, lymphnode metastasis, tumor necrosis, microvessel density, estrogen and progesterone receptor negativity, and HER-2/neu positivity were associated with higher grade of tumor.

CONCLUSIONS

The traditional morphological factors including the histological type, grade, tumor size, lymphovascular invasion, lymph node status, presence of necrosis, stromal reaction, and microvascular density (MVD) count are relatively simple but robust prognostic factors to assess, while the hormonal and genetic status not only have prognostic value but are useful predictive marker for adjuvant chemotherapy. Hence, the status of these various prognostic factors should form the basis of all routine histopathological reports in cases of breast cancer for better management.

Treatment with anti-NAP monoclonal antibody reduces disease severity in murine model of novel angiogenic protein-induced or ovalbumin-induced arthritis

Rheumatoid arthritis (RA) is a polyarticular inflammatory, angiogenic disease. Synovial angiogenesis contributes to inflammation in RA. In this study we have developed an arthritic model in rats using a novel angiogenic protein (NAP), isolated from human synovial fluid of RA patients. We produced anti-NAP monoclonal antibodies (mAbs) and investigated the therapeutic efficacy of the same in adjuvant-induced or NAP-induced arthritis as a model of human RA. The treatment of arthritic rats with anti-NAP mAbs resulted in effective amelioration of paw oedema, radiological arthritic characteristics, serum levels of vascular endothelial growth factor (VEGF) and NAP, compared to that of untreated arthritic animals. Further, profiling of angiogenic markers such as synovial microvessel density, angiogenesis, CD31, VEGF and fms-like tyrosine kinase (Flt1) by immunohistochemistry both in arthritic and anti-NAP mAb-treated animals revealed the efficacy of mAb as an anti-angiogenic functional antibody. Therefore, NAP may be an attractive target to design anti-angiogenic and anti-arthritic therapies to control the pathogenesis of arthritis.

Primary non-Hodgkin lymphoma of the colon among patients in the Veterans Affairs Health System

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Background: Primary non-Hodgkin lymphoma (NHL) of the colon is rare. There are no randomized controlled trials describing treatment outcomes for this tumor. We provide the largest descriptive study of this tumor to date.

Methods: Retrospective analysis of 109 patients diagnosed with primary non-Hodgkin lymphoma of the colon from 1995 to 2008 was done via the Veteran's Affairs Central Cancer Registry. By definition, all cases presented with a lymphomatous involvement of the colon as the first manifestation of their disease with no previous diagnosis of NHL of any type or site. Demographic, staging, histology, treatment, and outcome data was recorded. Lymphomas were classified as aggressive versus indolent based on their histology.

Results: There were 36,260 colon cancers diagnosed in 1995-2008 of which 109 (0.3%) were primary non-Hodgkin colon lymphomas. The median age of diagnosis was 67 years. 55 pts had aggressive disease, 27 pts had indolent disease, and 27 pts had inadequate histological data. Diffuse large B cell lymphoma (73%) was the most common aggressive lymphoma whereas it was marginal zone (56%) in the indolent group. The indolent group had 5- year survival rate of 76.9% compared to 48.6% for the aggressive group. Both groups had received different treatment regimens as seen in the Table with variable mean survival outcomes.

Conclusions: Our data suggests addition of postoperative adjuvant chemotherapy appears superior to surgery alone in the treatment of aggressive disease whereas it does not appear to provide any benefit in the treatment of indolent disease. However, patient numbers are too small to draw definite conclusions and warrant future investigation in multinational randomized fashion.

[Table: see text]

No significant financial relationships to disclose.

Morbidity Profiles of People Living With HIV/AIDS in Urban and Rural Inpatient and Outpatient Settings in Karnataka, South India

We examined the morbidity profiles associated with people living with HIV infection in an urban HIV inpatient treatment site near the city of Bangalore, in southern Karnataka state, south India, and in a rural outpatient site in northern Karnataka. Data from March 2007 until July 2008 were analyzed. The urban cohort comprised 432 patients, and the most common comorbid conditions were unexplained prolonged fever (50.2%) and oral candidiasis (42.6%). The rural cohort comprised 2374 patients, and the most common comorbid conditions were unexplained prolonged fever (58.8%), minor mucocutaneous infections (58.4%), and recurrent upper respiratory tract infections (52.3%). With less than 1% of patients in rural areas on treatment for tuberculosis (vs over one third in the urban cohort), tuberculosis is likely significantly underdiagnosed in rural areas. In addition, only 2.6% of rural outpatients who were eligible for antiretroviral treatment (ART), per Government of India guidelines, were actually on ART, compared to 31.6% of the urban population.

Somatic p16(INK4a) loss accelerates melanomagenesis

Loss of p16^INK4a–RB and ARF–p53 tumor suppressor pathways, as well as activation of RAS–RAF signaling, is seen in a majority of human melanomas. Although heterozygous germline mutations of p16^INK4a are associated with familial melanoma, most melanomas result from somatic genetic events: often p16^INK4a loss and N-RAS or B-RAF mutational activation, with a minority possessing alternative genetic alterations such as activating mutations in K-RAS and/or p53 inactivation. To generate a murine model of melanoma featuring some of these somatic genetic events, we engineered a novel conditional p16^INK4a-null allele and combined this allele with a melanocyte-specific, inducible CRE recombinase strain, a conditional p53-null allele and a loxP-stop-loxP activatable oncogenic K-Ras allele. We found potent synergy between melanocyte-specific activation of K-Ras and loss of p16^INK4a and/or p53 in melanomagenesis. Mice harboring melanocyte-specific activated K-Ras and loss of p16^INK4a and/or p53 developed invasive, unpigmented and nonmetastatic melanomas with short latency and high penetrance. In addition, the capacity of these somatic genetic events to rapidly induce melanomas in adult mice suggests that melanocytes remain susceptible to transformation throughout adulthood.

Mutational analysis of the candidate tumor suppressor gene ING1 in Indian oral squamous cell carcinoma

ING1, a recently identified candidate tumor suppressor gene, involved in the p53 signaling pathway is mapped at chromosome 13q34. Since loss of heterozygosity at 13q34 has been reported in squamous cell carcinoma of head and neck, we screened for mutations in ING1 by polymerase chain reaction-single strand conformation polymorphism in 71 oral squamous cell carcinomas (OSCC) from India, 15 of which were known to harbor p53 mutations. A single polymorphism (G to A) was detected in 14 (19.7%) of the tumors analyzed. No mutation was observed in any of the 71 OSCCs analyzed. These results suggest that ING1 is not a target for mutational inactivation in OSCC of Indians.

Mutation profile of the p53, fhit, p16INK4a/p19ARF and H-ras genes in Indian breast carcinomas

Breast cancer is the second most prevalent cancer affecting Indian women. Genetic alterations of oncogenes and tumor suppressor genes were attributed to the development of breast carcinomas. In the present study, human breast tumor DNAs from untreated, non-familial, Indian patients were analysed for the presence of mutations in p53, fhit, p16INK4a/p19ARF and H-ras genes. Polymerase chain reaction-single strand conformation polymorphism and sequencing analysis were used to detect point mutations. Exons 5-8 of p53, exons 1-2 of p16INK4a, exon 2 of p19ARF, exons 5-9 of fhit gene and exons 1-2 of H-ras genes were amplified and analysed individually using exon-flanking primers. Only 12% of the tumors had mutation in p53, 8% had mutation in fhit gene and none of the tumors showed evidence for mutation in p16INK4a/p19ARF and H-ras genes. Tumor B18 exhibited two novel mutations in the p53 gene, ATGright curved arrow GTG (Metright curved arrow Val) at codon 237 and AATright curved arrow GAT (Asnright curved arrow Asp) at codon 263. Both of these mutations are hitherto unreported in breast carcinomas. Tumor B20 had a non-sense mutation CGAright curved arrow TGA (Argright curved arrow Stop) at codon 306 of p53 gene. In fhit gene, tumor B1 exhibited TTCTright curved arrow TACT mutation at intron 8 and tumor B15 had a silent mutation GAGright curved arrow GAA (Gluright curved arrow Glu) at codon 123. Our results indicate that, among the genes analysed, the p53 gene was more frequently mutated than fhit, p16INK4a/p19ARF and H-ras genes in Indian mammary tumors. Transcribable point mutations of fhit gene were found to be extremely uncommon in these tumors. Mutations in the above genes are mutually exclusive and are infrequent in fhit, p16INK4a/p19ARF and H-ras genes suggesting that these genes may not play a major role in Indian breast carcinomas. However, the significant frequency of mutations in the p53 gene suggest that p53 could be one of the genes involved in the genesis of sporadic breast carcinomas in Indian women.

The p16INK4alpha/p19ARF gene mutations are infrequent and are mutually exclusive to p53 mutations in Indian oral squamous cell carcinomas

Eighty-seven untreated primary oral squamous cell carcinomas (SCCs) associated with betel quid and tobacco chewing from Indian patients were analysed for the presence of mutations in the commonly shared exon 2 of p16INK4alpha/p19ARF genes. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequencing analysis were used to detect mutations. SSCP analysis indicated that only 9% (8/87) of the tumours had mutation in p16INK4alpha/p19ARF genes. Seventy-two tumours studied here were previously analysed for p53 mutations and 21% (15/72) of them were found to have mutations in p53 gene. Only one tumour was found to have mutation at both p53 and p16INK4alpha/p19ARF genes. Thus, the mutation rates observed were 21% for p53, 9% for p16INK4alpha/p19ARF, and 1% for both. Sequencing analysis revealed two types of mutations; i) G to C (GCAG to CCAG) transversion type mutation at intron 1-exon 2 splice junction and ii) another C to T transition type mutation resulting in CGA to TGA changing arginine to a termination codon at p16INK4alpha gene codon 80 and the same mutation will alter codon 94 of p19ARF gene from CCG to CTG (proline to leucine). These results suggest that p16INK4alpha/p19ARF mutations are less frequent than p53 mutations in Indian oral SCCs. The p53 and p16INK4alpha/p19ARF mutational events are independent and are mutually exclusive suggesting that mutational inactivation of either p53 or p16INK4alpha/p19ARF may alleviate the need for the inactivation of the other gene.

Low incidence of p53 mutations in betel quid and tobacco chewing-associated oral squamous carcinoma from India

Mutations of the p53 tumor suppressor gene have been found to be the single most frequent event in human cancers. In India and other southeast Asian countries tobacco chewing with betel quid was attributed to be the major factor in oral carcinogenesis. We have analyzed 72 untreated primary oral squamous cell carcinomas (SCCs) for mutations in the tumor suppressor gene p53 exons 4-9 by PCR-SSCP and DNA sequencing. Sequencing analysis revealed 16 missense mutations, one silent mutation in codon 307 and four A to G substitution polymorphism in codon 213. The incidence of p53 mutation was 21% (15 of 72) excluding the polymorphism and the silent mutation. Eight mutations were clustered in codons 266-282 of exon 8. Of the total mutation events 37.5% were G to A transitions and 31.3% were G to T transversions. These results indicate the possible involvement of tobacco derived nitrosamines and their adducts in the genesis of oral cancer among Indians.