Risk of Radiation-Associated Secondary Malignancies among Patients with Breast Cancer Harboring TP53 Germline Variants

PURPOSE/OBJECTIVE(S)

Radiation-associated malignancies are rare and poorly understood. TP53 encodes a multifunctional protein that maintains genome integrity and is the most common somatically mutated gene in cancer. Germline pathogenic variants of TP53 predispose carriers to several cancers comprising the Li-Fraumeni syndrome. It is hypothesized that carriers are also at increased risk of radiotherapy (RT)-associated secondary malignancies; however, reports are mixed. We evaluated the risk of secondary malignancies after breast RT among patients with Li-Fraumeni syndrome.

MATERIALS/METHODS

This multi-institutional cohort study included carriers of TP53 germline variants who underwent surgical treatment for breast cancer between 1980 and 2020. Patients were stratified based on germline TP53 classification (pathogenic variants [PV] vs variants of uncertain significance [VUS]). The primary outcome of interest was the cumulative incidence risk of developing an in-field secondary cancer after radiotherapy for primary breast carcinoma.

RESULTS

Ninety-one patients (57 PV and 34 VUS) were evaluated with a median age of 36 years (interquartile range [IQR] 31, 42) and a median follow up of 7.9 years (IQR 4.7, 14.4). Among those with PV who received RT (n = 22), 4 secondary non-breast cancers developed in the radiation field (15-year cumulative incidence 19% [95% CI: 4-43%]), whereas, among those with PV who did not receive RT (n = 35), 0 secondary non-breast cancers were observed in the treated breast (15-year cumulative incidence 0%; p = 0.043). We observed 3 radiation-associated sarcomas among patients with PV who received RT (15-year risk 12% [95% CI 2-33%]) compared with 0 among those who did not receive RT (p = 0.08). No RT-associated sarcomas were observed among 18 patients with TP53 VUS who received RT. RT was not associated with overall survival, despite higher T and N breast cancer stage among those receiving RT (p = 0.33). As expected, patients with PV were more likely than those with VUS to develop any secondary cancer following breast cancer treatment (15-year risk: 54% [95% CI: 33-72%] vs. 14% [95% CI: 3-36%]).

CONCLUSION

Carriers of pathogenic variants of TP53 are at elevated risk of developing secondary malignancies after breast cancer treatment. This population is at particular risk of developing in-field secondary cancers following RT. This iatrogenic risk must be weighed against the anticipated therapeutic benefit of tumor control. Shared decision making is crucial in the radiotherapeutic management of breast cancer patients harboring the Li-Fraumeni syndrome.

Changes in the multidisciplinary management of rectal cancer from 2009 to 2015 and associated improvements in short-term outcomes

AIM

Significant recent changes in management of locally advanced rectal cancer (LARC) include preoperative staging, use of extended neoadjuvant therapies and minimally invasive surgery (MIS). This study was aimed at characterizing these changes and associated short-term outcomes.

METHOD

We retrospectively analysed treatment and outcome data from patients with T3/4 or N+ LARC ≤ 15 cm from the anal verge who were evaluated at a comprehensive cancer centre in 2009-2015.

RESULTS

In total, 798 patients were identified and grouped into five cohorts based on treatment year: 2009-2010, 2011, 2012, 2013 and 2014-2015. Temporal changes included increased reliance on MRI staging, from 57% in 2009-2010 to 98% in 2014-2015 (P < 0.001); increased use of total neoadjuvant therapy, from 17% to 76% (P < 0.001); and increased use of MIS, from 33% to 70% (P < 0.001). Concurrently, median hospital stay decreased (from 7 to 5 days; P < 0.001), as did the rates of Grade III-V complications (from 13% to 7%; P < 0.05), surgical site infections (from 24% to 8%; P < 0.001), anastomotic leak (from 11% to 3%; P < 0.05) and positive circumferential resection margin (from 9% to 4%; P < 0.05). TNM downstaging increased from 62% to 74% (P = 0.002).

CONCLUSION

Shifts toward MRI-based staging, total neoadjuvant therapy and MIS occurred between 2009 and 2015. Over the same period, treatment responses improved, and lengths of stay and the incidence of complications decreased.

Meeting report from the joint IARC-NCI international cancer seminar series: a focus on colorectal cancer

Despite significant progress in our understanding of the etiology, biology and genetics of colorectal cancer, as well as important clinical advances, it remains the third most frequently diagnosed cancer worldwide and is the second leading cause of cancer death. Based on demographic projections, the global burden of colorectal cancer would be expected to rise by 72% from 1.8 million new cases in 2018 to over 3 million in 2040 with substantial increases anticipated in low- and middle-income countries. In this meeting report, we summarize the content of a joint workshop led by the National Cancer Institute and the International Agency for Research on Cancer, which was held to summarize the important achievements that have been made in our understanding of colorectal cancer etiology, genetics, early detection and treatment and to identify key research questions that remain to be addressed.

Abstract P2-09-24: Information preferences and short-term psychological responses to multiplex genetic testing among individuals at risk for hereditary breast cancer

Background: Multiplex genetic testing involves the simultaneous analysis of a panel of known cancer susceptibility genes. Although efficient and cost-effective, multiplex testing presents several challenges for patients and clinicians: these tests provide information about high and moderate penetrance genes of varying clinical utility, patients cannot choose which specific genes are tested, and multiple variants of uncertain significance can be identified at once. Multiplex testing is being increasingly integrated into clinical care, yet little is known about patients' preferences, uptake, or psychological responses to these tests.

Methods: To address this gap, we examined two data sources: Sample A) a cross-sectional clinical ascertainment of 189 patients evaluated for hereditary breast and other cancer syndromes (89% female), and Sample B) an ongoing prospective research study of multiplex testing among 194 breast cancer patients and survivors who previously received uninformative BRCA1/2 results (99% female, 84% white, ages 27-76, 60% had BRCA1/2 testing in the past year).

Results: In Sample A, 32% declined clinical multiplex testing in favor of more targeted testing. Female patients were more likely than males to decline (p=0.004). Self-reported reasons for declining included: concerns about uncertain clinical utility of moderate penetrance genes (51% of patients) and variants of uncertain significance (38%), feeling emotionally overwhelmed (23%), and not seeing the value of multiplex testing (20%). In Sample B, participants were allowed to select which information to receive from a multiplex test; 16% chose to learn less than all of the information available (e.g., not genes unrelated to breast/ovarian cancer, not genes without established clinical utility, not CDH1 or TP53). Information preferences were unrelated to demographic (age, race, time since cancer diagnosis and BRCA1/2 testing) and self-reported psychological factors (baseline genetic testing-related distress, uncertainty, and positive experiences; anxiety; depression). Participants who chose to learn all possible information reported greater concerns about their children's cancer risk than did those who chose to learn less information (p=0.01). Participants reported a small increase in both genetic testing-related distress and positive experiences from before testing to 1 week after receiving results (p&lt;0.001). In multivariable analyses controlling for baseline psychological functioning, only non-white race was consistently associated with significantly increased post-result anxiety, depression, and genetic testing-related distress and uncertainty. Participants who had BRCA1/2 testing one or more years ago also reported fewer positive experiences 1 week after receiving results.

Conclusions: Together, these findings demonstrate that a sizable minority of patients have important concerns regarding multiplex tests that may limit their uptake of this novel testing, and suggest that some patients may prefer to customize the specific risk information provided. Results also highlight characteristics of those at risk for poorer emotional outcomes following testing; these individuals may benefit from additional support in this context.

Citation Format: Robson ME, Gaissert P, Salo-Mullen EE, Amoroso K, Sheehan M, Berliner JL, Trottier M, Arnold AG, Sekhri N, Marcell V, Siegel B, Harlan Fleischut M, Hay JL, Walsh MF, Kauff ND, Stadler ZK, Offit K, Hamilton JG. Information preferences and short-term psychological responses to multiplex genetic testing among individuals at risk for hereditary breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-24.

Abstract P4-19-01: Attitudes of medical oncologists towards research biopsies

Background:

There is increasing interest in studying tissue from patients (pts) with metastatic breast cancer (MBC). Historically, limited tissue has been available. Possible barriers to research biopsies (bx) include pt and provider opinions; the contribution of each factor is unknown.

Methods:

309 academic breast medical oncologists (MOs) identified from the websites of each of the National Cancer Institute - designated cancer centers were invited to complete either a self-administered paper or online survey. Eligible MOs (MOs who saw breast cancer pts and who saw pts 4 hours/week.) were asked to predict what proportion of their pts with MBC would consent to additional bx (ABs, additional bx performed with a clinically indicated bx) or research purposes only bx(RPOBs, research bx performed as a standalone procedure). They were also asked about their comfort levels in asking pts with MBC to consider participating in ABs or RPOBs for various organs. Median values are reported. Two-sided Fisher's exact test was used to compare categorical variables using a a level of .05.

Results:

191 (101F,85M, 5 unknown) eligible MOs completed the survey. 29 MOs were ineligible (response rate = 191/280,68%). Median age was 50 (Range 33-80). Median years of oncology experience was 15 (Range 1-45). MOs predicted that 90%, 75%, 70% and 50%, of their pts would definitely/probably consider ABs of blood, skin, breast, or liver respectively. MOs predicted that 90%, 60%, 33%, and 20% of their pts would definitely/probably consider RPOBs of blood, skin, breast, or liver. 98% (95% CI 96%-100%), 96% (95% CI 92%-98%), 93% (95% CI 88%-96%) and 70% (95% CI 63%-77%) of MOs were very/somewhat comfortable asking pts for an AB of blood, skin, breast and liver respectively. 98% (95% CI 95%-99%), 93% (95% CI 89%-96%), 78% (95% CI 72%-84%) and 50% (95% CI 43%-58%) of MOs were very/somewhat comfortable asking pts to participate in a RPOB of blood, skin, breast and liver respectively.

No demographic characteristics (eg. sex, age) were associated with MOs’ comfort levels of asking pts to have an AB of blood, skin and breast.

Factors associated with increased comfort discussing an AB of the liver were: age &lt; 50 years (p = 0.01), in practice for &lt; 15 years (p = 0.01), ≥ 1 pt enrolled on clinical trials per month (p = 0.02), or having pts who had undergone bx for research in prior 3 months (p&lt;0.01).

MOs with ≥ 4 patients enrolled on clinical trials/month or whose pts had undergone research bx in the past 3 months were more likely to feel comfortable asking pts to have a RPOB of the breast (p&lt;0.01; p&lt;0.01) or liver (p = 0.03; p&lt;0.01).

The 3 most common reasons why MOs were reluctant to refer pts for participation in an AB include risk of a bx procedure (n = 128, 67%), pain/discomfort of a bx (n = 125, 65%), and logistical barriers (n = 42, 22%). These reasons are similar for RPOB; risk of a bx procedure, (n = 137, 72%), pain/discomfort of a bx (n = 134, 70%), and inconvenience to pt (time involved, travel, etc) (n = 58, 30%).

Conclusions:

Many MOs predict that the majority of their MBC pts will consider ABs of various organs. However, this decreases with RPOBs, particularly as the procedure becomes more invasive. More research is needed to understand factors that may influence MOs’ comfort levels asking pts to participate in such studies.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-19-01.

Attitudes of patients with metastatic breast cancer toward research biopsies

BACKGROUND

Research studies involving human tissue are increasingly common. However, patients' attitudes toward research biopsies are not well characterized, particularly when the biopsies are carried out outside the context of therapeutic trials.

PATIENTS AND METHODS

One hundred sixty patients with metastatic breast cancer (MBC) from two academic (n = 80) and two community (n = 80) hospitals completed a 29-item self-administered survey to evaluate their willingness to consider providing research purposes only biopsies (RPOBs) (as a stand-alone procedure) and additional biopsies (ABs) (additional needle passes at the time of a clinically indicated biopsy).

RESULTS

Eighty-two (51%) of 160 patients would consider having RPOBs, of which 42 (53%) and 40 (50%) patients were from academic and community hospitals, respectively. Patients who had more prior biopsies were less likely to consider RPOBs (RR = 0.6, 95% CI: 0.4-1.0, P = 0.03). Of 160 patients, 115 (72%) patients would consider having ABs. Of these, 64 (80%) and 51 (64%) patients from academic and community hospitals, respectively, would consider ABs (RR = 1.2, 95% CI: 1.0-1.5, P = 0.03).

CONCLUSIONS

Many patients with MBC in both academic and community settings report willingness to consider undergoing biopsies for research. Further research is needed to understand ethical, logistical and provider-based barriers to broader participation in such studies.

Abstract P2-16-04: Attitudes of metastatic breast cancer patients towards research biopsies

Background: In the era of molecularly targeted therapy, developing an understanding of the molecular basis of cancer is a principal or secondary goal of many research studies. For this reason, studies collecting tissue for research purposes are increasingly common. Understanding patients' attitudes towards research biopsies may lead to improvement in accrual to research biopsy studies.

Methods: Patients with metastatic breast cancer from two academic and two community hospitals completed a self-administered paper survey consisting of 29 questions in clinic to evaluate their willingness to consider providing additional biopsies (additional biopsy performed with a clinically indicated biopsy) and research purposes only biopsies (RPOB) (research biopsy performed as a stand alone procedure).

Results: 160 patients (n = 80 academic, n=80 community) completed the survey, with a response rate of 98%. As expected, demographic variables differed between sites, with patients from academic sites likely to be younger (p = 0.01), more educated (p = 0.002), employed (p = 0.01), have prior trial participation (P &lt;0.001) and have a longer travel time (P &lt;0.0001). 64 (80%) academic patients and 51 (64%) community patients would definitely or probably consider additional biopsies. 42 (53%) academic patients and 40 (50%) community patients would consider RPOB.

In univariate analyses of patients' willingness to have additional biopsies, patients in academic sites were more likely to agree to additional biopsies than those at community sites (RR = 1.2, 95% CI 1.0–1.5, p = 0.03). Statistically significant differences based on demographic characteristics such as age, education, marital status, prior trial participation, number of prior biopsies, and travel time were not observed.

For RPOB, patients having had more prior biopsies were less likely to consider research biopsies (RR = 0.6, 95% CI 0.4–1.0, p = 0.03). The following variables did not reach statistical significance: type of practice, age, education, marital status, prior trial participation, and travel time.

Patients' willingness in both academic and community sites to consider RPOB declined with more invasive biopsies. Although differences were observed, none were statistically significant between academic and community; skin (56%, 65%), bone marrow (30%, 27%), breast (43%, 49%) or liver (24%, 19%).

Of the 13/160 (8%) patients who would not consider additional biopsies, the most common reasons cited included pain or discomfort (n = 8/13, 62%), risk of biopsy (n = 8/13, 62%) and anxiety related to the biopsy (n = 6/13, 46%). Of the 37/160 (23%) patients who would not consider RPOB, the most common reasons cited included pain or discomfort (n = 23/37, 62%), risk of biopsy (n = 15/37, 41%) and inconvenience of the procedure to the patient (n = 13/37, 35%).

Conclusions: The majority of patients in this study indicated they would consider research biopsies, with a larger proportion willing to consider additional biopsies; patients seen at academic hospitals were more likely to consider additional biopsies compared to those seen at community hospitals. Breast cancer patients' willingness to undergo research biopsies may be higher than generally expected by clinicians and may not be the primary barrier to obtaining research biopsies.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-16-04.

De novo CDH1 mutation in a family presenting with early-onset diffuse gastric cancer

In this report, we describe the first concluded case of a de novo germline mutation in CDH1 in a hereditary diffuse gastric cancer (HDGC) kindred. The incident case was a woman with a personal history of Hodgkin's lymphoma and diffuse gastric cancer, who was then confirmed to have a CDH1 mutation (c.1792 C>T (R598X)). The patient's mother was found to have the same CDH1 germline mutation; however, neither maternal grandparent was found to carry the mutation, thus leading to a conclusion that the proband's mother's mutation is of de novo origin. This case highlights the importance of recognition of the HDGC syndrome and of testing for CDH1 germline mutations in young individuals with diffuse gastric cancer without a family history of the disease.

Prevalence of BRCA1 mutations in triple negative breast cancer (BC)

508

Background: 90% of BCs in women with germline BRCA1 mutations are ER, PR and HER2 negative (so-called “Triple Negatives”), and 80–90% of triple negative BCs are “basal-like” by DNA microarray and IHC analysis. Prevalence of germline BRCA1 mutations among women with triple negative BC may therefore, be elevated, and underestimated by available calculation models, which do not take tumor features into account. Methods: We randomly identified 200 women from the Dana-Farber/Harvard Cancer Center SPORE annotated specimen bank with histologically confirmed primary invasive, ER, PR and HER2 negative BC. Myriad prevalence tables for BRCA1 were used to estimate the probability that each subject carried a BRCA1 mutation according to age at BC diagnosis, family and personal history of breast and/or ovarian cancer, and Ashkenazi Jewish ancestry. Full sequencing analysis for BRCA1 germline mutations is in progress. Results: The median age at diagnosis of triple negative BC was 49 years (range 26–79). The majority of tumors were high grade (89%) ductal (95%) carcinomas; median tumor size was 2 cm, 50% had positive nodes. 3 patients had a personal history of ovarian cancer and 13 reported Ashkenazi Jewish ancestry. 44% had at least one first or second degree relative with BC; 12% had at least one relative with ovarian cancer. The estimated probability of detecting a BRCA1 mutation according to the Myriad tables ranged from 0.019 to 0.386 (median 0.039): the total expected number of BRCA1 mutations was 11. In a subgroup of 23 patients (12%), who had undergone clinical testing, 2.7 BRCA1 and 1.4 BRCA2 mutations were expected according to the Myriad tables. However, 9 deleterious BRCA1 mutations (39.1%) were found; 2 patients had a BRCA2 mutation (8.7%). Conclusions: The relative excess of BRCA1 mutations in a small group of patients with triple negative BC suggests that established risk factors alone may underestimate the prevalence of BRCA1 mutations among women with this BC subtype. We anticipate that complete BRCA1 analysis of our entire group will more definitively estimate the prevalence BRCA1 mutations among women with triple negative BC.

No significant financial relationships to disclose.