Abstract P5-06-11: Serum thymidine kinase-1 activity (TKa) as a prognostic marker in premenopausal women with hormone receptor positive (HR+) operable breast cancer (BC)

Introduction: Thymidine kinase is an established marker of cancer cell proliferation and its activity can be measured in blood. We and others have recently shown that baseline and dynamic evaluation of circulating thymidine kinase activity (TKa) during treatment gives prognostic and predictive information in patients with HR+, HER2-negative metastatic BC treated with endocrine therapy alone, as well as in the setting of CDK4/6 inhibition. However, there is limited data regarding the role of TKa as a prognostic biomarker in operable BC. Here we present a retrospective analysis of TKa in serum samples collected in a cohort of premenopausal women with operable BC enrolled in a phase III adjuvant multicenter clinical trial (NCT00201851).

Materials and methods: Serum samples were available for 644 (87%) of participants prospectively enrolled in a randomized trial between 2003 and 2009 in South East Asia. All women were premenopausal, had stage II-IIIB HR+ operable BC and uniformly received bilateral surgical oophorectomy concurrent with mastectomy followed by tamoxifen alone for five years. Patients did not receive chemotherapy or targeted therapy pre- or post-operatively. Participants were randomized in the study according to the timing of surgery with respect to the phase of the menstrual cycle. Serum samples were collected preoperatively on the day of surgery. Serum TKa was measured using the ELISA-based DiviTum™ assay (Biovica, Sweden). TKa analysis was performed at a central laboratory, blind to clinical data. Baseline TKa values were correlated with clinico-pathological characteristics and clinical outcome. Clinical outcome was estimated using the Kaplan-Meier method.

Results: The majority of patients had both estrogen and progesterone receptor positive tumors (94% and 92% respectively), 65% were HER2 negative (18% positive; 17% unknown). Most had pT2 or pT3 disease (60% and 27% respectively), and more than half were node-positive (pN0 42%, pN1 27%, pN2 19%, pN3 11%, pNx 1%). The overall median TKa value was 65.4 Du/L. At five years, patients with a baseline TKa value below the median had a disease-free survival (DFS) rate of 75% versus 61% in those with a baseline over the median (HR 1.82, 95% CI 1.37-2.4, p<0.001). Similar results were observed when women with HER2+ disease were excluded from analysis (HR 1.71, 95% CI 1.21-2.42, p=0.0025). Further prognostic precision was achieved when TKa values were divided by quartiles, with a 5 year DFS rate of 81%, 69%, 63% and 58% observed in the 1st, 2nd, 3rd and 4th quartiles respectively. After adjusting for major prognostic factors and randomization arm, TKa remained an independent marker.

Conclusions: This study shows pre-operative TKa measured in serum is a strong prognostic marker in a large cohort of women with HR+ operable BC uniformly treated within a clinical trial. The notable rate of recurrence seen within this cohort of patients derived from non-high income countries may be mainly attributed to the relative degree of disease burden at diagnosis. TKa may be seen as a potential circulating marker of proliferation akin to tumor Ki67, which may provide useful prognostic information to guide adjuvant therapies.

Citation Format: Luca Malorni, Ilenia Migliaccio, Chiara Biagioni, Lorenzo Rossi, Irene De Santo, Richard L Love, Amelia McCartney, Mattias Bergqvist, Martina Bonechi, Francesca De Luca, Francesca Galardi, Matteo Benelli, Dario Romagnoli, Emanuela Risi, Laura Biganzoli, Adriano Laudico, Nguyen Van Dinh, Angelo Di Leo. Serum thymidine kinase-1 activity (TKa) as a prognostic marker in premenopausal women with hormone receptor positive (HR+) operable breast cancer (BC) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-06-11.

Cancer survival in Manila, Philippines, 1994-1995

The population-based cancer registry in Manila, Philippines, called the Philippine Cancer Society-Manila Cancer Registry, was established in 1983. Cancer registration is pursued by active methods. The registry contributed survival data on a random sample of total incident cancers of breast (500), cervix (500), colon and rectum (300) registered in 1994-1995. Follow-up has been carried out by passive and active methods, with median follow-up ranging between 15-33 months for different cancers. The proportion of histologically verified diagnosis for various cancers ranged between 78-88%; 74-83% of the total submitted cases were included for survival analysis. Complete follow-up at five years was available in 75-82% of cases. Five-year age-standardized relative survival rates was the highest for cancer of the breast (52%) followed by colon (49%), cervix (36%) and rectum (31%). Five-year relative survival by age group did not display any pattern or trend and was fluctuating. A decreasing survival with increasing extent of disease was noted for all cancers.

Breast cancer survival in Rizal, Philippines, 1996-1997

The department of health-Rizal cancer registry (DOH-RCR) was the first population-based cancer registry in the Philippines, established in 1974. Even though cancer is reportable by legislation, cancer registration is pursued by active methods. Data on survival from cancer of the breast registered in 1996-1997 are reported. Followup was carried out by passive and active methods. The proportion of cases with a histological confirmation of cancer diagnosis was 90%; death certificates only (DCOs) constituted 6%; 81% of the total registered were included for the survival analysis. Complete follow-up at five years from the incidence date was 30%. Relative survival rates at one, three and five years were 89%, 56% and 37%, respectively. Five-year age-standardized relative survival was 35%. Five-year relative survival by age group did not display any pattern or trend, and was fluctuating. A majority of cases were diagnosed with a regional spread of disease (44%) followed by localized stage (17%). Five-year absolute survival ratesby extent of disease were localized (65%), regional (35%), distant metastasis (12%) and unknown (35%). Thetrend of 5-year survival for breast cancer decreased from 46% in 1987 to 37% in 1996-1997.

Geographic and ethnic differences in childhood leukaemia and lymphoma survival: comparisons of Philippine residents, Asian Americans and Caucasians in the United States

Background:

Childhood cancer survival estimates from developing nations are rare.

Methods:

Using the US SEER and the Manila and Rizal Cancer Registry databases in the Philippines, 5-year survival for childhood leukaemia and lymphoma in 2001–2005 among Asian Americans were compared with both Filipinos and Caucasians in the United States. Estimates for patients in the United States in earlier time periods were compared with that of Philippine residents to estimate delay in achievements of comparable levels of survival.

Results:

Childhood leukaemia and lymphoma relative survival was much lower in Filipinos living in the Philippines (32.9 and 47.7%) than in Asian Americans (80.1 and 90.5%) and Caucasians (81.9 and 87%). Achievement of comparable survival rates of Philippine residents lagged behind by 20 to >30 years compared with patients in the United States.

Conclusions:

The large differences in survival estimates of US populations and Philippine residents highlight the deficiencies of paediatric cancer care delivery in the Philippines. The long survival lag underlines the need for major improvements in access to diagnostic and treatment facilities.

Cumulative incidence trends of selected cancer sites in a Philippine population from 1983 to 2002: a joinpoint analysis

BACKGROUND

Few studies have investigated incidence trends in the Philippines.

METHODS

From the databases of the Manila Cancer Registry, cumulative cancer incidence rates were determined for the five most common cancers for both sexes combined. Using joinpoint analysis, incidence trends for 1983-2002 were estimated.

RESULTS

Among females, increasing trends were found for breast, 5% annual change, lung (0.5%) and colorectal (1.5%) cancers. Decreasing trends were found for cancers of the liver (-1.2%) and cervix (-1.9%). Among males, increasing trends were found for lung cancer (0.5%), whereas liver cancer rates have been decreasing (-1.0%). Colorectal cancer rates fluctuated.

CONCLUSION

Certain sites showed declining incidence trends, but incidence trends for lifestyle-related cancers continue to rise. The prevention of infection-related cancers should also receive priority, particularly by vaccination programmes.

Cancer survival differences between European countries and an urban population from the Philippines

BACKGROUND

The EUROCARE study has disclosed large variations of survival across Europe, with the magnitude varying, depending on cancer site. Comparisons of these rates with those from the developing countries are rare, but important in evaluating international cancer care discrepancies. This study aimed to provide up-to-date estimates of cancer survival in a Philippine urban population, and to compare these with those observed in the European countries.

METHODS

Using the results from the EUROCARE-4 study, the survival estimates of the European patients who were diagnosed in 1995-99 and followed till December 2003 were abstracted. From randomly selected samples drawn from the Manila and Rizal Cancer Registries, 5-year survival was estimated for nine common cancers. Age-adjusted survival estimates were then compared between the Philippine population and Europeans.

RESULTS

In comparison to the European mean, survival estimates for the Philippine residents were lower for most cancers, with differences ranging from 2 to 40% units. Differences with European country-specific estimates were large for cancers of the breast and cervix, where early detection is possible, and for leukaemia, where treatment regimens are costly, highlighting the importance of health care. Smaller discrepancies were observed for stomach, liver and lung cancers, with the 5-year relative survival being similar to the Philippines and to many European countries. A survival advantage was seen though for the Philippine residents for ovarian cancer.

CONCLUSION

Apart from efforts to prevent cancers, improvements in cancer control and making early diagnosis and treatment more accessible remain major challenges, both in the Philippines and in the European nations.

Inter-country and ethnic variation in colorectal cancer survival: comparisons between a Philippine population, Filipino-Americans and Caucasians

BACKGROUND

Previous population-based studies showed differences in international and within country colorectal cancer survival estimates, but few investigated the role of prognostic factors. Using a "high resolution approach", we aimed to determine the effect of ethnicity and health care by comparing Filipino-Americans with Philippine residents, who have the same ethnicity, and with Caucasians living in the US, who have the same health care system.

METHODS

Using databases from the Manila and Rizal Cancer Registries and the United States Surveillance, Epidemiology and End Results, age-adjusted five-year absolute and relative survival estimates were computed and compared between Filipino-American colorectal cancer patients, cancer patients from the Philippines and Caucasian patients. Cox proportional hazards modelling was used to determine factors affecting survival differences.

RESULTS

Much lower 5-year relative survival estimates were obtained for Philippine residents (37%) as compared to those in Filipino-Americans (60.3%) and Caucasians (62.4%). Differences in age, stage and receipt of surgery explained a large proportion of the survival differences between Philippine residents and Filipino-Americans. However, strong excess risk of death for Philippine residents remained after controlling for these and other variables (relative risk, RR, 2.03, 95% confidence interval, 95% CI, 1.83-2.25).

CONCLUSIONS

Strong survival disadvantages of Philippine residents compared to Filipino-American patients were disclosed, which most likely reflect differences in access to and utilization of health care. Health education and advocacy, for both patients and health practitioners, should likewise be given priority.

Cancer epidemiology and control in peninsular and island South-East Asia - past, present and future

Malaysia, Brunei, Singapore, Indonesia, East Timor and the Philippines constitute peninsular and island South-East Asia. For reasons of largely shared ethnicity, with Chinese elements added to the basic Austromalaysian populations, as well as geographical contiguity, they can be usefully grouped together for studies of chronic disease prevalence and underlying risk factors. The fact of problems are shared in common, particularly regarding increasing cancer rates, underlines the necessity for a coordinated approach to research and development of control measures. To provide a knowledge base, the present review of available data for cancer registration, epidemiology and control was conducted. The most prevalent cancer site in males is the lung, followed by the liver, colon or the prostate in the majority of cases, while breast and cervical cancers predominate in most female populations. However, there are interesting differences among the racial groups, particularly regarding the stomach. General tendencies for increase in adenocarcinomas but decrease in squamous cell carcinomas and gastric cancer, point to change in environmental influence over time. Variation in risk factors depends to some extent on the level of economic development but overall the countries of the region face similar challenges in achieving effective cancer control. A major task is persuading the general populace of the efficacy of early detection and clinical treatment.

Ovarian cancer survival population differences: a "high resolution study" comparing Philippine residents, and Filipino-Americans and Caucasians living in the US

Background

In contrast to most other forms of cancer, data from some developing and developed countries show surprisingly similar survival rates for ovarian cancer. We aimed to compare ovarian cancer survival in Philippine residents, Filipino-Americans and Caucasians living in the US, using a high resolution approach, taking potential differences in prognostic factors into account.

Methods

Using databases from the SEER 13 and from the Manila and Rizal Cancer Registries, age-adjusted five-year absolute and relative survival estimates were computed using the period analysis method and compared between Filipino-American ovarian cancer patients with cancer patients from the Philippines and Caucasians in the US. Cox proportional hazards modelling was used to determine factors affecting survival differences.

Results

Despite more favorable distribution of age and cancer morphology and similar stage distribution, 5-year absolute and relative survival were lower in Philippine residents (Absolute survival, AS, 44%, Standard Error, SE, 2.9 and Relative survival, RS, 49.7%, SE, 3.7) than in Filipino-Americans (AS, 51.3%, SE, 3.1 and RS, 54.1%, SE, 3.4). After adjustment for these and additional covariates, strong excess risk of death for Philippine residents was found (Relative Risk, RR, 2.45, 95% confidence interval, 95% CI, 1.99-3.01). In contrast, no significant differences were found between Filipino-Americans and Caucasians living in the US.

Conclusion

Multivariate analyses disclosed strong survival disadvantages of Philippine residents compared to Filipino-American patients, for which differences in access to health care might have played an important role. Survival is no worse among Filipino-Americans than among Caucasians living in the US.

Cancer survival discrepancies in developed and developing countries: comparisons between the Philippines and the United States

Despite the availability of population-based cancer survival data from the developed and developing countries, comparisons remain very few. Such comparisons are important to assess the magnitude of survival discrepancies and to disentangle the impact of ethnic background and health care access on cancer survival. Using the SEER 13 database and databases from the Manila and Rizal Cancer Registries in the Philippines, a 5-year relative survival for 9 common cancers in 1998–2002 of Filipino-American cancer patients were compared with both cancer patients from the Philippines, having the same ethnicity, and Caucasians in the United States, being exposed to a similar societal environment and the same health care system. Survival estimates were much higher for the Filipino-Americans than the Philippine resident population, with particularly large differences (more than 20–30% units) for cancers with good prognosis if diagnosed and treated early (colorectal, breast and cervix), or those with expensive treatment regimens (leukaemias). Filipino-Americans and Caucasians showed very similar survival for all cancer sites except stomach cancer (30.7 vs 23.2%) and leukaemias (37.8 vs 48.4%). The very large differences in the survival estimates of Filipino-Americans and the Philippine resident population highlight the importance of the access to and utilisation of diagnostic and therapeutic facilities in developing countries. Survival differences in stomach cancer and leukaemia between Filipino-Americans and Caucasians in the United States most likely reflect biological factors rather than the differences in access to health care.

Epidemiology and clinicopathology of breast cancer in metro Manila and Rizal Province, Philippines

The breast cancer incidence in the Philippines is among the highest in Asia. Age-standardized incidence rates (ASR) in Metro Manila and Rizal Province derived from the Philippine Cancer Society-Manila Cancer Registry and the Department of Health-Rizal Cancer Registry showed increase from 1980 to 2002, and were significantly higher in 7 cities in Metro Manila and significantly lower in 14 cities/municipalities mostly in Rizal Province. The AJCC Clinical Stage did not change from 1993 to 2002 among incident cases, the average distribution being: I= 5%, IIA= 20%, IIB= 18%, IIIA= 9%, IIIB= 10%, IV= 11%, Unknown= 28%. The International Agency for Research on Cancer attempted to run a randomized screening trial in 1995-1997 in the Philippines based on clinical breast examination by trained nurses and midwives. Unfortunately, even after home visits by a team equipped to perform needle biopsy, only 35% of screen-positive cases eventually had a diagnostic test. The estimated prevalence of BRCA mutations among unselected patients in the Philippine General Hospital (PGH) in 1998 was 5.1%, with a prevalence of 4.1% for BRCA2 mutations alone. There is a continuing effort at improving IHC hormone receptor testing at PGH, particularly on early fixation in buffered formalin. It was observed that hormone receptor-positive proportions tended to be higher in core needle biopsy specimens (72%) compared to mastectomy specimens (65%). During the years 1991, 1994 and 1997, 97% of incident cases of early breast cancer underwent modified radical mastectomy, 18% had postoperative radiotherapy, 51% had adjuvant hormone treatment and 47% received adjuvant chemotherapy. Survival of incident cases in 1993 to 2002 was compared to that of Filipino-Americans and Caucasians in the SEER 13 database. The age-adjusted 5-year relative survival, using period analysis, of Metro Manila residents, Filipino-Americans and Caucasians were 58.6%, 89.6% and 88.3% respectively.

Outcome of screening by clinical examination of the breast in a trial in the Philippines

The value of screening by Clinical Examination of the Breast (CBE) as a means of reducing mortality from breast cancer (BC) is not established. The issue is relevant, as CBE may be a suitable option for countries in economic transition, where incidence rates are on the increase but limited resources do not permit screening by mammography. Our aims were to assess whether mass screening by CBE carried out by trained para-medical personnel is feasible in an urban population of a low-income country, and its efficacy in reducing BC mortality. Our study was designed as a randomised controlled trial of the effect on BC mortality of 5 annual CBE carried out by trained nurses. The target population was women aged 35-64 years, resident in 12 municipalities of the National Capital Region of Manila, Philippines. The units of randomization were the 202 health centres (HC) within the selected municipalities. During 1995 nurses and midwives were recruited and trained in performing CBE. The first round of screening took place in 1996-1997. The intervention however showed a refractory attitude of the population with respect to clinical follow-up and was discontinued after the completion of the first screening round. Cases of breast cancer occurring in the study population during 1996-1999 were identified by the 2 local population-based registries. In the single screening round 151,168 women were interviewed and offered CBE, 92% accepted (138,392), 3,479 were detected positive for a lump and referred for diagnosis. Of these only 1220 women (35%) completed diagnostic follow-up, whereas 42.4% actively refused further investigation even with home visits, and 22.5% were not traced. Of 53 cases that occurred among screen-positive women in the 2 years after CBE only 34 were diagnosed through the intervention. Eighty cases occurred among screen-negative women. The test sensitivity for CBE repeated annually was 53.2%. The actual sensitivity of the programme was 25.6% and positive predictive value 1%. Screen-detected cases were non-significantly less advanced than the others. Previous studies have shown that most breast cancer cases in the Philippines present at advanced stages and have an unfavourable outcome. Although CBE undertaken by health workers seems to offer a cost-effective approach to reducing mortality, the sensitivity of the screening programme in the real context was low. Moreover, in this relatively well-educated population, cultural and logistic barriers to seeking diagnosis and treatment persist and need to be addressed before any screening programme is introduced.