A combined analysis of two prospective randomised studies exploring the impact of extended post-radiation temozolomide on survival outcomes in newly diagnosed glioblastoma

PURPOSE

The optimal duration of post-radiation temozolomide in newly diagnosed glioblastoma remains unclear, with no published phase III randomised trials. Standard-of-care stipulates 6 months. However, in routine care, it is often extended to 12 months, despite lacking robust supporting data.

METHODS

GEINO14-01 (Spain) and EX-TEM (Australia) studies enrolled glioblastoma patients without progression at the end of 6 months post-radiation temozolomide. Participants were randomised 1:1 to six additional months of temozolomide or observation. Primary endpoint was 6-month progression free survival from date of randomisation (6mPFS). Secondary endpoints included overall survival (OS) and toxicity. 204 patients were required to detect an improvement in 6mPFS from 50 to 60% (80% power). Neither study recruited sufficient patients. We performed a combined analysis of individual patient data.

RESULTS

205 patients were recruited: 159 in GEINO14-01 (2014-2018) and 46 in EX-TEM (2019-2022). Median follow-up was 20.0 and 14.5 months. Baseline characteristics were balanced. There was no significant improvement in 6mPFS (57.2% vs 64.0%, OR0.75, p = 0.4), nor across any subgroups, including MGMT methylated; PFS (HR0.92, p = 0.59, median 7.8 vs 9.7 months); or OS (HR1.03, p = 0.87, median 20.1 vs 19.4 months). During treatment extension, 64% experienced any grade adverse event, mainly fatigue and gastrointestinal (both 54%). Only a minority required treatment changes: 4.5% dose delay, 7.5% dose reduction, 1.5% temozolomide discontinuation.

CONCLUSION

For glioblastoma patients, extending post-radiation temozolomide from 6 to 12 months is well tolerated but does not improve 6mPFS. We could not identify any subset that benefitted from extended treatment. Six months should remain standard-of-care.

Abstract P4-09-02: Validation of iPrevent using the prospective family study cohort (ProF-SC)

Background: iPrevent (https://www.petermac.org/iprevent) provides women with highly-tailored risk management information after first estimating their breast cancer (BC) risk using the established risk prediction models, IBIS and BOADICEA. iPrevent has an internal switching algorithm that governs which model is used for each woman, depending on her risk factor data (i.e. LCIS/atypical hyperplasia status, BRCA status, and cancer family history). This study assessed the calibration and discriminatory accuracy of the 10-year BC risk estimates provided by iPrevent. Methods: Subjects were 16,574 women in the ProF-SC, aged 18-70 years and without BC or bilateral mastectomy at recruitment. After 10 years follow-up, 655 women (4%) were diagnosed with invasive BC. A “batch mode” for iPrevent is not available, so the iPrevent-assigned cumulative 10-year invasive BC risks were calculated by entering self-reported risk factors at cohort entry into either the IBIS (10,169 women) or BOADICEA (6,405 women) software packages (according to the iPrevent switching algorithm). To assess calibration, the mean iPrevent-assigned risk was compared with the mean 10-year observed invasive BC incidence, using a chi-squared goodness-of-fit statistic for the whole cohort, and by quartiles of risk. To evaluate discriminatory accuracy, the overall area under the receiver operating characteristic curve (AUC) for the development of invasive BC within 10 years was computed. Data were censored at date of invasive or in situ BC diagnosis, bilateral mastectomy, death, loss to follow-up, or at 10 years of follow-up. Results: For the whole cohort, iPrevent assigned risk was well-calibrated – 690 expected BCs (E) 655 observed (O) (E/O=1.05, 95% CI: 0.98-1.14), although for women in the highest risk quartile, i.e. >6% 10-year risk, E/O=1.19, 95% CI: 1.07-1.32. The AUC was 0.70, 95% CI: 0.68-0.72. Conclusions: iPrevent is well calibrated overall and has good discriminatory accuracy for predicting 10-year BC risk, thus justifying its clinical use.

Citation Format: Phillips K-A, Liao Y, Collins IM, Buchsbaum R, Weideman P, Bickerstaffe A, MacInnis RJ, kConFab Investigators, Cuzick J, Antoniou A, Andrulis IL, John EM, Daly MB, Buys SS, Hopper JL, Terry MB. Validation of iPrevent using the prospective family study cohort (ProF-SC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-09-02.

Consumer and clinician perspectives on personalising breast cancer prevention information

BACKGROUND

Personalised prevention of breast cancer has focused on women at very high risk, yet most breast cancers occur in women at average, or moderately increased risk (≤moderate risk).

OBJECTIVES

To determine; 1) interest of women at ≤ moderate risk (consumers) in personalised information about breast cancer risk; 2) familial cancer clinicians' (FCCs) perspective on managing women at ≤ moderate risk, and; 3) both consumers' and FCCs reactions to iPrevent, a personalised breast cancer risk assessment and risk management decision support tool.

METHODS

Seven focus groups on breast cancer risk were conducted with 49 participants; 27 consumers and 22 FCCs. Data were analysed thematically.

RESULTS

Consumers reported some misconceptions, low trust in primary care practitioners for breast cancer prevention advice and frustration that they often lacked tailored advice about breast cancer risk. They expressed interest in receiving personalised risk information using iPrevent. FCCs reported an inadequate workforce to advise women at ≤ moderate risk and reacted positively to the potential of iPrevent to assist.

CONCLUSIONS

While highlighting a potential role for iPrevent, several outstanding issues remain. For personalised prevention of breast cancer to extend beyond women at high risk, we must harness women's interest in receiving tailored information about breast cancer prevention and identify a workforce willing to advise women.

Abstract P4-11-02: Acceptability and usability of iPrevent, a web-based decision support tool for assessment and management of breast cancer risk

Background: iPrevent estimates an individual's personal BC risk, using either the IBIS or BOADICEA algorithms, and provides tailored risk management information on screening, lifestyle modifications, risk-reducing surgery and risk-reducing medication. It is designed to be used collaboratively by women and their clinicians. The purpose of this pre-implementation pilot study was to assess the clinical usability and acceptability of the iPrevent prototype, and to identify barriers to clinical implementation. Exploratory aims investigated patients' BC worry, anxiety, risk perception and knowledge before and after using iPrevent. Methods: Eligible clinicians worked in primary care (PC), breast surgical (BS) or genetics clinics (GC). Their female patients were eligible if aged 18-70 years with no personal cancer history. Clinicians were familiarized with iPrevent using hypothetical cases, then actor scenarios, and lastly iPrevent was trialed with patients. All participants completed the System Usability Scale (SUS) and an acceptability questionnaire 2 weeks after using iPrevent. Patients also completed the Lerman BC Worry Scale, Spielberger State-Trait Anxiety Inventory, and BC risk perception and prevention knowledge questionnaires before and 2 weeks after using the tool. Data were summarized using descriptive statistics. Results: 63 participants comprising 20 clinicians (median age 47 years, 8 PC, 6 BS, 6 GC) and 43 patients (median age 38 years, 16% high risk, 51% moderate risk, 33% average risk) were recruited. Usability was rated above average (SUS score >68) by most clinicians (68%) and patients (76%). Most (79% of clinicians, 81% of patients) agreed iPrevent was 'easy to use', although 10 (53%) clinicians and 10 (27%) patients reported that it was too long. Most clinicians (84%) and patients (86%) found iPrevent 'very' or 'somewhat' helpful. 89% of participants reported that iPrevent provided the right amount of information. 5% reported to 'rarely' or 'not at all' worry about BC before iPrevent, and 29% after use. 25% of patients reported less impact of worrying about BC after iPrevent, 47% were unchanged and 28% reported more impact of worrying about BC after iPrevent use. State anxiety remained the same. 87% of patients correctly reported their risk category after using iPrevent® compared with 40% before. BC prevention knowledge improved for most questions. Conclusions: iPrevent has high usability and acceptability. Exploratory analyses suggest that iPrevent may also improve patients' BC risk perception and knowledge without adversely affecting anxiety or BC worry. Because concerns about length could be a barrier to implementation, data entry has been abbreviated in the modified version of iPrevent that will be publically available.

Citation Format: Phillips K-A, Lo L, Bressel M, Collins IM, Emery J, Weideman P, Keogh L, Steel E, Bickerstaffe A, Mann GB, Trainer A, Hopper JL, Antoniou AC, Cuzick J, Butow P. Acceptability and usability of iPrevent, a web-based decision support tool for assessment and management of breast cancer risk [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 P4-11-02.

Abstract P4-13-10: Do BRCA1 and BRCA2 mutation carriers have an earlier natural menopause than their non-carrier relatives: A study from the Kathleen Cuningham Foundation Consortium For Research Into Familial Breast Cancer (kConFab)

BACKGROUND: Limited data from the in vitro fertilisation setting suggest that germline BRCA1 mutations are associated with occult primary ovarian insufficiency. We examined whether carriers of a BRCA1 or BRCA2 mutation have earlier natural menopause than their non-carrier relatives.

PATIENTS AND METHODS: Eligible subjects were female mutation carriers and tested non-carriers from families segregating BRCA1 or BRCA2 mutations enrolled in KConFab. Women who had not been tested for the family mutation and those with primary amenorrhoea were excluded. Data were self-reported using uniform questionnaires completed at cohort entry and every 3 years thereafter. Age at natural menopause (NM) was defined as age at cessation of menses for ≥ 12 months in the absence of other causes. Cox proportional hazards analysis was applied, modelling time in years from birth to NM, adjusting for year of birth (continuous), body mass index (continuous), ever regular cigarette smoking (no, yes), and ever regular alcohol use (no, yes). Analysis time was censored at the earliest of: cessation of menses for 12 months in the absence of other reasons (natural menopause), last follow-up, pelvic surgery including oophorectomy or hysterectomy, commencement of hormone replacement therapy or Tamoxifen as a risk reducing medication, or any cancer diagnosis. Hazard ratios (HR) were estimated as a measure of how rapidly mutation carriers reach natural menopause relative to non-carriers.

RESULTS: No difference was observed in the rate at which carriers and non-carriers went through natural menopause, regardless of the gene mutated in the families. The adjusted hazard ratio estimates were 0.97, (95% CI 0.69–1.35, p = 0.8) for BRCA1 mutation carriers versus non-carriers and 1.02, (95%CI 0.72–1.44, p = 0.9) for BRCA2 mutation carriers versus non-carriers.

Strategies for fertility preservation after chemotherapy: awareness among Irish cancer specialists

The potential effect on fertility for patients undergoing cancer treatments is an important issue. The aim of this study was to assess awareness of fertility preservation strategies among cancer specialists involved in the management of young women with malignancy. A 10 question survey was sent to 94 cancer specialists in Ireland, comprising 28 medical oncologists, 32 haematologists and 34 breast surgeons, assessing awareness of; guidelines, facilities in Ireland, and potential barriers to referral. Fifty of 94 responded (53% response rate). Awareness of current success rates associated with assisted reproductive therapy was poor. Ten respondents (20%) identified the estimated time delay to the delivery of chemotherapy due to fertility preservation. Three important potential barriers to referral were identified; time delays, poor prognosis disease and clinical features of the cancer. Awareness of the impact of reduced fertility is important in these patients but early consideration is vital.