Discordance in Recommendation Between Next-Generation Sequencing Test Reports and Molecular Tumor Boards in India

PURPOSE

Accurate understanding of the genomic and transcriptomic data provided by next-generation sequencing (NGS) is essential for the effective utilization of precision oncology. Molecular tumor boards (MTBs) aim to translate the complex data in NGS reports into effective clinical interventions. Often, MTB treatment recommendations differ from those in the NGS reports. In this study, we analyze the discordance between these recommendations and the rationales behind the discordances, in a non-high-income setting, with international input to evaluate the necessity of MTB in clinical practice.

METHODS

We collated data from MTB that were virtually hosted in Chennai, India. We included patients with malignancies who had NGS reports on solid tissue or liquid biopsies, and excluded those with incomplete data. MTB forms and NGS reports of each clinical case were analyzed and evaluated for recommendation concordance. Concordance was defined as an agreement between the first recommendation in the MTB forms and the therapeutic recommendations suggested in the NGS report. Discordance was the absence of the said agreement. The rationales for discordance were identified and documented.

RESULTS

Seventy MTB reports were analyzed with 49 cases meeting the inclusion criteria. The recommendation discordance was 49% (24 of 49). Discordant recommendations were mainly due to low level of evidence for the drug (75% of cases).

CONCLUSION

The discordance between MTB and NGS vendor recommendations highlights the clinical utility of MTB. The educational experiences provided by this initiative are an example of how virtual academic collaborations can enhance patient care and provider education across geographic borders.

Efficacy of Oral SERDs in the treatment of ER+, HER2 - metastatic breast cancer, a stratified analysis of the ESR1 wild type and mutant subgroups

BACKGROUND

Oral SERDs are a novel drug class that have been developed to counteract resistance due to ESR1 mutations. Several SERDs have emerged from phase 2 and 3 trials, with the FDA limiting approval for Elacestrant to patients with ESR1mt tumours despite PFS benefit in the overall population. However, questions remain on whether patients with ESR1wt tumours stand to benefit from oral SERDs.

PATIENTS AND METHODS

Manuscripts and conference presentations of Randomised Controlled Trials were extracted after a systematic search of Embase, PubMed and Cochrane from inception until January 21,2023. RCTs investigating the efficacy of oral SERDs versus endocrine therapy for ER positive, HER2 negative advanced breast cancer, and which reported the Kaplan Meier (KM) curves of PFS in the overall and ESR1 mutant (ESR1mt) population were selected. A graphical reconstructive algorithm was applied to estimate time-to-event outcomes from reported KM curves in all overall and ESR1mt cohorts. A bipartite matching algorithm, KMSubtraction, was used to derive survival data for unreported (ESR1wt) subgroups. An individual patient data (IPD) meta-analysis was then pursued, pooling data by ESR1 mutation status in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Cochrane Guidelines for IPD.

RESULTS

The randomized clinical trials ACELERA, AMEERA-3, EMERALD and SERENA-2 were included, totalling 1290 patients. In the pooled analysis of the overall cohort, PFS benefit was observed with oral SERDs when compared with treatment of physicians choice (TPC) (HR 0.783, 95%CI 0.681-0.900, p<0.001). In the ESR1mt subgroup, oral SERDs demonstrated improved PFS (HR 0.557, 95%CI 0.440-0.705, p<0.001) compared to TPC. In the ESR1wt subgroup, oral SERDs demonstrated no significant PFS benefit (HR 0.944, 95%CI 0.783-1.138, p=0.543) when compared to TPC.

CONCLUSIONS

The results of this IPD meta-analysis suggests that PFS benefit in the overall population is mainly driven by the ESR1mt subgroup.

Real-world PARPi treatment patterns and outcomes among patients with metastatic breast cancer

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Background: PARP inhibitors (PARPi) improves PFS among patients (pts) with HER2-ve metastatic breast cancer (MBC) and a BRCA1/2 mutation compared to physician choice of chemotherapy. The objective of this retrospective analysis was to look at the prognostic outcome associated with the use of PARPi therapy among pts with MBC in the real world setting. Methods: We utilized a federated network of de-identified health data representing approximately 84 million pt lives available through the TriNetX Research Network. We identified 767 pts with MBC treated with a PARPi. Overall survival (OS) was computed using the Kaplan Meier product limit method. Propensity score matching was performed on all comparisons of OS. Matching variables included age groups, prior platinum therapy, prior genitourinary malignancies, and secondary metastasis location. Results: Mean age was 56.3yrs. 718 pts had HER2- disease and 49pts had HER2+ disease. Median OS was 55.0m and 44.4m among pts with HER2- and HER2+ disease respectively. Median OS among was 58.3m and 48.6m among patients with HR+/HER2- and TNBC respectively(p = 0.18). Among pts with HR+/HER2- disease, 50.2% received PARPi in combination with endocrine therapy and 43.5% received CDK4/6i. Median OS among pts who received CDK4/6i + endocrine therapy prior to a PARPi and those that never received a CDK4/6i was 55.1m and 36.9m, respectively(p = 0.01). Among pts with TNBC, median OS among those that received PARPi prior to chemotherapy compared to those who received PARPi after chemotherapy was 52.5m and 47.6m respectively (p = 0.97). 169 HER2- pts had brain metastases. Median OS among pts who had brain metastases was 36.9m among pts with HR+/HER2- disease and 22.5m among pts with TNBC(p = 0.01). Among pts with no brain metastases, median OS was 60.6m among pts with HR+/HER2- disease and 56.3m among pts with TNBC(p = 0.91). Median OS among pts who were rechallenged with a PARPi compared to those who were not rechallenged with a PARPi was 58.3m vs 42m respectively (p = 0.05). Conclusions: To our knowledge this is the first data set to report activity of CDK4/6i among pts with HR+/HER2- MBC who received a PARPi, with an observed 18m OS advantage compared to pts who did not receive a CDK4/6i. In absence of brain metastases OS of pts with TNBC and HR+/HER2- is similar when treated with a PARPi.

Use of RET inhibitors among patients with advanced NSCLC: A real-world evidence analysis

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Background: RET rearrangements are found in approximately 1% to 2% of patients with NSCLC. Two selective RET inhibitors have been FDA approved based on phase 1/2 data showing significant activity among patients with advanced NSCLC that have RETrearrangements. The objective of this retrospective analysis was to look at the prognostic outcome associated with the use of selective RET inhibitors (sRETi) and multikinase inhibitors (MKIs) that have been used to target RET fusions among pts with NSCLC in the real-world setting. Methods: We utilized a federated network of de-identified health data representing approximately 84 million pt lives available through the TriNetX Research Network. We identified 1,215 pts with metastatic NSCLC treated with selpercatinib, praseltinib, cabozantanib or vandetanib. Overall survival (OS) was evaluated with Kaplan Meier statistics and compared between patients treated with either sRETi (selpercatinib or pralsetinib) vs either MKI (cabozantanib or vandetanib). Results: Mean age among all anti-RET treated patients was 67.6 years. 518 pts (43%) were female and 697 (57%) were male. 531 (39.6%), 205 (15.3%) and 605 (45.1%) pts had received selpercatinib, pralsetinib, and either cabozantinib or vandetinib, respectively. 56.6% of pts receiving pralsetinib received prior selpercatinib. Among pts receiving sRETi, 39.7%, 6.4%, 11.2%, and 32.4% received sRETi in the 0-3, 3-6, 6-12, and 12+ months after metastatic diagnosis, respectively. Among pts receiving MKIs, 17.0%, 8.4%, 13.3%, and 44.9% received MKIs in the 0-3, 3-6, 6-12, and 12+ months after metastatic diagnosis. Median OS after treatment with MKIs and sRETi during any time frame was 16.3m and 25.0m, respectively (p < 0.01). Among pts treated with MKIs vs sRETi during the 0-3, 3-6, 6-12, and 12+ months after metastatic diagnosis, 1-year survival probability after treatment was 59.7% vs 55.9% (p = 0.39), 45.0% vs 83.1% (p < 0.01), 53.9% vs 82.2% (p < 0.01), and 57.7% vs 87.1% (p < 0.01), respectively. 30% of pts of all anti-RET treated patients had brain metastases, and median OS from index metastasis among pts with and without brain metastases was 31.4m and 63.1m respectively (p < 0.01). Conclusions: To our knowledge this is the first real world data set to show a > 8m improvement in OS with the use of sRETi compared to MKIs among pts with metastatic NSCLC. OS improvements may be more significant in pts treated in later lines of therapy with sRETi.

Efficacy of CDK4/6i in the visceral crisis setting: Result from a real-world database

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Background: The combination of the CDK4/6 inhibitors(CDK4/6i) and endocrine therapy has improved overall survival(OS) in patients(pts) with either endocrine sensitive or resistant disease who are not in visceral crisis. The goal of this retrospective analysis of a real world database was to look at the efficacy of CDK4/6i among pts with hormone receptor positive (HR+ve)/HER2-ve metastatic breast cancer(MBC) who present with visceral crisis at diagnosis. Methods: For this analysis, we utilized a federated network of de-identified health data representing approximately 64 million patient lives available through the TriNetX Platform. We identified 5966 pts who had HR+ve/HER2-ve MBC diagnosed between 2015 and 2020. OS was computed using the Kaplan Meier product limit method. Propensity score matching was performed on all comparisons of survival. Visceral crisis was defined as either liver metastases with liver dysfunction, lymphangitis with dyspnea or the presence of pancytopenia. Results: 906(15%) pts received CDK4/6i. OS any time after treatment among pts who did and did not receive CDK4/6i was significantly different (p=0.0002) favoring the group receiving CDK4/6i, with median OS at 59.6 months and 46.2 months and 2-year OS at 71.6% and 61.4% respectively. Among pts who received CDK4/6i versus another treatment as first line therapy, OS was significantly different(HR 0.7, 95%CI 0.57 – 0.86, p<0.0001), and median OS was 59.6 months and 41.5 months respectively. 336 pts with HR+ve mbc presented with visceral crisis at the time of diagnosis of whom 61(18%) received CDK4/6i therapy as first line therapy. Median OS among pts who did and did not have visceral crisis at diagnosis and received treatment was 8.1 months and 210 months respectively. OS any time after initial treatment was significantly different among pts with visceral crisis who did and did not receive CDK4/6i (p=0.01), with 2-year OS at 26.1% and 8.1% and median OS at 11 months and 6 months respectively Conclusions: The use of CDK4/6i in the presence of visceral crisis at diagnosis was associated with a 5 month improvement in OS compared to chemotherapy. Future clinical trials should explore the use of CDK4/6i in the setting of visceral crisis.

Impact of race on the utilization and efficacy of CDK4/6i: Result from a real world database

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Background: The combination of the CDK4/6 inhibitors(CDK4/6i) and endocrine therapy has improved overall survival(OS) in patients(pts) with endocrine sensitive or resistant disease. Only 43 pts of black race were included in the first line trials making interpretation of results in this group difficult. The goal of this retrospective analysis of a real world database was to look at the clinical utilization and prognostic impact of CDK4/6i among pts of white and black race who have hormone receptor positive (HR+ve)/HER2-ve metastatic breast cancer(MBC). Methods: For this analysis, we utilized a federated network of de-identified health data representing approximately 64 million pt lives available through the TriNetX Platform. We identified 5400pts with information on race who had HR+ve/HER2-ve MBC diagnosed between 2015 and 2020. OS was computed using the Kaplan Meier product limit method. Propensity score matching was performed on all comparisons of survival, matching patients from two cohorts on secondary malignancy location (as noted in ICD-10 diagnosis coding)and age group. Results: 4182 white pts and 1199 black pts were identified, and 1,194 pts in each group remained after matching. Mean age at diagnosis was 57.2 and 58.3 yrs among white and black pts respectively. OS among pts of white and black race was significantly different (HR 1.4, 95%CI 1.12-1.70, p < 0.0001), and 2-yr OS was 87.8% and 82.6% respectively. 599(20%) pts of white race and 148(18%) pts of black race received CDK4/6i therapy. The rate of uptake of use CDK4/6i was initially similar in 2015 however by 2020 some differences were observed with rate of uptake being 190 per 1000 and 264 per 1000 among pts of black and white race respectively. Pts of each race appeared to have a similar prevalence of CDK4/6i per line of treatment. OS among pts who received CDK4/6i and were of white and black race was not significantly different(HR 0.94, 95% CI 0.65- 1.38, p = 0.80), and 2-year OS was 69.9% and 69.5% respectively. Conclusions: Overall the proportional use of CDK4/6i was similar among pts of black and white and race. Although initial uptake appears to have been consistent between Black and White pts, further attention is necessary to assess potential disparities in use as time progresses. The use of CDK4/6i in the setting of HR+ve/HER2-ve MBC diminishes the differences in outcome between the two races.

Development of a telegenetics program in the Asia-Pacific/Middle East region

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Background: BRCA mutations is emerging as an agnostic marker for PARPi. Accessibility to genetic counselling is limited due to shortage of manpower and access to institutions that provide it. Our aim was to look at the incidence of pathogenic germline mutations in India/UAE and develop a virtual pathway, aimed at increasing accessibility to genetic counselling. Methods: 864 patients(pts) were tested in the UAE and India for germline mutations. Based on discussion between physicians and patients, an urgent need for genetic counseling was identified. A virtual platform (telegenetics) was constructed for those who sought genetic counseling due to a personal or family history of malignancies. Referral of pts was either self-based or through a treating physician. Primary goals included 1) ease of access for pts, 2) increase comprehension of the indications, implications and consequences of genetic testing, 3) decrease physician time in the clinic. 10 questions were developed determine pt and physician satisfaction. Results: 241(28.9%)pts had a pathogenic variant in BRCA1/BRCA. 115pts were enrolled in the pilot phase of the tele genetics program; all physician referred. Counselling was by a dedicated trained genetic counsellor through voice-call(43.5%), video-conferencing(47.8%) or in person when requested (8.7%). All pts completed a satisfaction survey. Majority of pts were comfortable sharing information on a virtual platform(80%), were happy with the quality of virtual connection(85%), and felt comfortable connecting with the genetic counselor(90%). Information is currently being collected from referring physicians. Conclusions: Our ongoing pilot phase reveals improved pt satisfaction and understanding of the information provided. A mobile application has been developed to enhance pt accessibility/convenience and physician connectivity with the testing phase of the app currently on going. To our knowledge this is the first tele genetics program to target the middle east/Asia pac region that is targeted to cope with increase in pt volumes, expand appropriate referrals, starting with pts who have a personal or family history of cancers, expanding to more complex high risk diseases over time.

Comparison of biomarkers among 34,855 GI cancer samples show heterogeneity of tumor types

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Background: Recent data indicate that biomarker driven use of targeted therapy and I/O-therapy among patients with GI cancer is associated with improved outcome. The presence of biomarkers varies broadly between different GI tumor types, highlighting the importance of comprehensive molecular profiling.To analyze the presence of various alterations in GI cancer samples of a large database, comparing congruency between various tumor types. Methods: A retrospective data analysis of 34855 GI cancer patients profiled at CARIS Life Sciences obtained from Jan 1st2010 till Sep 14th2018 was performed. GI tumors were classified as : CRC, esophageal/gastric/GIST, small intestine, pancreatic/hepatobiliary/liver. Technologies used to analyze the biomarkers: IHC for PD-L1, MMR and Her2, and DNA-NGS for EGFR, BRAF, KRAS, NRAS, MET-CNV, TMB, MSI, POLE and BRCA1/2. Results: Median age was 61 (range 18-89 years). 51.5% was CRC (n = 18047), 15.5 % was esophageal /Gastric/GIST (n = 5470), 3% was small intestinal cancer (n = 886) and 30% was pancreatic/hepatobiliary/liver cancer (n = 10452). Information on biomarkers was available from 2931 cases for MET amplification to 28536 for RAS information. Overall, the most common finding was a pathogenic RAS-mutation (either KRAS or NRAS) in 7650 cases (26.81%), the rarest one was a mutation in EGFR in 12 cases (0.06%). Higher rate of HER2 amplification was observed among pts with esophageal/gastric/GIST tumors (6.5%) in comparison to tumors at other GI sites ( ~1.5%). High TMB was seen among patient with CRC and small intestine tumors (~7%) while it was lowest among pancreatic cancer (1.8%). Compared to other GI sites lower MSI /MMR deficiency rates were observed in pancreatic /hepatobiliary tumors, significantly higher PD-L1 positivity was observed in gastrooesophageal cancer types, increased MET-amplifications in gastrooesophageal and small intestinal cancer types and lower RAS-mutation rate in gastrooesophageal cancer. Conclusions: Molecular profiling analyzing druggable biomarkers can help identify patients with increased likelihood for benefit from immune-checkpoint-inhibitors and targeted therapies. Further investigations are needed to evaluate the different findings in various GI cancer types.

Comparison of biomarkers among 34855 GI cancer samples shows heterogeneity of tumor types

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Background: Recent data indicate that biomarker driven use of targeted therapy and I/O-therapy among patients with GI cancer is associated with improved outcome. The presence of biomarkers varies broadly between different GI tumor types, highlighting the importance of comprehensive molecular profiling. To analyze the presence of various alterations in GI cancer samples of a large database, comparing congruency between various tumor types. Methods: A retrospective data analysis of 34855 GI cancer patients profiled at CARIS Life Sciences obtained from Jan 1, 2010 till Sep 14, 2018 was performed. GI tumors were classified as CRC, esophageal/gastric/GIST, small intestine, pancreatic/hepatobiliary/liver. Technologies used to analyze the biomarkers: IHC for PD-L1, MMR and Her2, and DNA-NGS for EGFR, BRAF, KRAS, NRAS, MET-CNV, TMB, MSI, POLE and BRCA1/2. Results: Median age was 61 range (18-89 years). 51.5% was CRC (n=18047), 15.5 % was esophageal/Gastric/GIST (n=5470), 3% was small intestinal cancer (n=886) and 30% was pancreatic/hepatobiliary/liver cancer (n=10452). Information on biomarkers was available from 2931 cases for MET amplification to 28536 for RAS mutation. Overall, the most common finding was a pathogenic RAS-mutation in 7650 cases (26.81%), the rarest one was a mutation in EGFR in 12 cases (0.06%). Higher rate of HER2 amplification was observed among pts with esophageal/gastric/GIST tumors (6.5%) in comparison to tumors at other GI sites ( ~1.5%). High TMB was seen among patient with CRC and small intestine tumors (~7%) while it was lowest among pancreatic cancer (1.8%). Compared to other GI sites lower MSI /MMR deficiency rates were observed in pancreatic /hepatobiliary tumors, significantly higher PD-L1 positivity was observed in gastrooesophageal cancer types, increased MET-amplifications in gastrooesophageal and small intestinal cancer types and lower RAS-mutation rate in gastrooesophageal cancer. Conclusions: Molecular profiling analyzing druggable biomarkers can help identify patients with increased likelihood for benefit from immune-checkpoint-inhibitors and targeted therapies. Further investigations are needed to evaluate the different findings in various GI cancer types.

Incidence and characteristics of breast cancer following a diagnosis of ductal carcinoma in situ

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Background: Recent data indicate that the incidence of DCIS is rising. The purpose of this retrospective population based study was to examine incidence of and factors that contribute to the development of a subsequent breast primary. Methods: Using the SEER registry we identified female pts with a primary DCIS diagnosed between 1990 to 2005. Pts who had an invasive or in situ malignancy diagnosed prior to a diagnosis of DCIS were excluded. Cumulative incidence of a subsequent breast primary (invasive/non invasive) was estimated and compared across groups using the Chi-square test. Multivariable logistic regression models were then fitted to determine factors that could predict for the development of a subsequent breast primary. Results: 96,130 pts were identified of whom 14,573 (15.2%) had subsequent primaries. 9,037 (62%) pts had a subsequent primary in the breast of which 5,915 (65.5%) pts had an invasive breast cancer. Among pts who developed an invasive breast cancer 68% had hormone receptor positive disease, 59% had grade I/II disease and 80% had stage I/II disease. 2 and 5-year cumulative incidence of developing a subsequent breast primary was 3.2% and 5.9% respectively. 2 and 5-year cumulative incidence of developing a subsequent invasive breast primary was 1.6% and 3.4% respectively. 5-year cumulative incidence of developing a subsequent breast primary among pts who were of white, black and other race was 5.8%, 6.8% and 6.1% respectively (P<0.001). In the multivariable logistic model the probability of developing a subsequent breast primary decreased with each increasing year of diagnosis of DCIS (OR 0.91, 95%CI 0.91-0.92, p<0.001). Other factors that predicted for the development of a subsequent breast primary included younger age at diagnosis, non-white race and lack of surgical or radiation therapy for DCIS. Conclusions: Our results indicate that a significant proportion of pts with a diagnosis of DCIS go on to develop invasive breast cancer and may warrant further investigation to determine biological risk factors, appropriate screening procedures and possible interventions to decrease incidence. Target groups that may benefit include pts who are young and of non white race at the time of diagnosis of DCIS.

Is the proportion of patients with synchronous stage IV breast cancer surviving > 2 years increasing over time?

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Background: Studies have shown a moderate increase in survival over time among pts with stageIV breast cancer. Median survival is approximately 2 yrs. The aim of this study was to evaluate trends over time of pts with synchronous stage IV disease who survive >2 yrs. Methods: Using the SEER registry we identified female pts with synchronous stage IV breast cancer diagnosed between 1990-2007. Pts were divided into 3 groups according to year of diagnosis(1990-1995, 1996-2000, 2001-2007). Probability of surviving more than >2 yrs was computed within each group. A multivariable logistic regression model was then fitted to determine the association between year of diagnosis and the probability of surviving >2 yrs after adjusting for other prognostic factors. Results: 22,492 pts were identified of whom 9,388 (41.7%) had a survival of >2 yrs. The probability of surviving >2 yrs was 36.2%, 40.1%, and 44.2% among pts diagnosed in periods 1990-1995, 1996-2000, and 2001-2007 respectively (p-value < 0.0001). The probability of surviving >2 yrs was 55.3% and 29.3% among pts with ER+ and ER- disease respectively (p-value <0.0001) and was 32.9% and 43.5% among pts of black and white race respectively (p-value <0.0001). In the multivariable model the probability of surviving >2 yrs increased with increasing year of diagnosis (OR 1.04, 95% CI 1.03-1.05, p <0.0001). Other factors significantly associated with an increased probability of surviving >2 yrs included radiation therapy, lower grade, younger age, hormone receptor (HR) positive disease and non-inflammatory disease. Interaction term between race and year of diagnosis was marginally significant, such that black pts had a more slowly increasing probability of surviving >2 yrs compared to whites (OR 0.97, 95% CI 0.96-1.00, p = 0.037). Interaction term between HR status and year of diagnosis was not significant. Conclusions: Our results indicate that among pts with synchronous stage IV breast cancer the probability of surviving >2 yrs has increased over time reflecting the introduction and FDA approval of multiple efficacious chemotherapeutic and endocrine therapeutic options. Of concern, the probability of surviving >2 yrs has increased more slowly among pts of black race.

Impact of surgery and radiation of the primary among women with de novo stage IV breast cancer

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Background: The aim of this retrospective study was to determine the impact of surgery(S) and radiation(R) therapy to the primary tumor among patients (pts) with stage IV denovo breast cancer. Methods: The SEER registry was used to identify pts with denovo stageIV breast cancer diagnosed between 1988 and 2008. Pts were divided into 4 groups based on type of treatment to primary tumor: both S+R, S alone, R alone, or no treatment of primary (no S/R). Breast cancer specific survival (BCS) was calculated from the date of diagnosis of breast cancer to the date of death from breast cancer or last follow up. Survival outcomes were estimated by the Kaplan-Meier method, and Cox models were fit to determine the association between treatment of primary and survival after adjusting for potential confounders (e.g age, grade, hormone receptor and race). Results: 25903 pts were identified; 4640 (17.9%) S+R, 6556 (25.3%) S, 4467 (17.2%) R, and 10240 (39.5%) no S/R. 1183 (4.6%) had surgery to sites other than the primary. Median age was 63 years. Median follow-up was 14 months. Median BCS was 23 months. Median BCS among pts who underwent S+R, S, R and no S/R was 36 months, 31 months, 18 months and 15 months respectively (p<0.0001). Among pts who underwent S+R, median BCS among pts who did and did not have surgery to sites other than primary was 50 months and 41 months respectively (p=0.029). Of the pts treated with S+R 10-year BCS was 18%. In the multivariable model compared to women who were in the no S/R group those who underwent S (HR= 0.59, 95%CI 0.55- 0.62,p<0.0001) and S+R (HR=0.51, 95%CI 0.47-0.55,p<0.0001) had decreased risk of death from breast cancer and those who underwent R (HR=1.13, 95% CI 1.04-1.21, p=0.002) had an increased risk of death from breast cancer. Pts who had surgery to sites other than the primary tumor had decreased risk of death from breast cancer compared to those who did not (HR=0.80, 95%CI 0.72-0.89,p<0.0001). Conclusions: Our results indicate that S+R of the primary breast tumor among pts with denovo stage IV breast cancer maybe associated with a decreased risk of death from breast cancer. A select subgroup of pts who undergo S+R may also benefit from surgery to sites other than the primary which may afford them maximum survival advantage.

Hormone receptor status and pathologic response of HER2-positive breast cancer treated with neoadjuvant chemotherapy and trastuzumab

BACKGROUND

The aim of this study was to compare the extent of pathologic response in patients with HER2-positive (HER2+) breast cancer treated with standard neoadjuvant chemotherapy, with or without trastuzumab (H), according to hormone receptor (HR) status.

PATIENTS AND METHODS

We included 199 patients with HER2+ breast cancer from three successive cohorts of neo-adjuvant chemotherapy on the basis of paclitaxel (Taxol) (P) administered weekly (w) or three weekly (3-w), followed by 5-fluorouracil (F), doxorubicin (A) or epirubicin (E), and cyclophosphamide (C). Residual cancer burden (RCB) was determined from pathologic review of the primary tumor and lymph nodes and was classified as pathologic complete response (pCR) or minimal (RCB-I), moderate (RCB-II), or extensive (RCB-III) residual disease.

RESULTS

In HR-positive (HR+) cancers, a higher rate of pathologic response (pCR/RCB-I) was observed with concurrent H + 3-wP/FEC (73%) than with 3-wP/FEC (34%, P = 0.002) or wP/FAC (47%; P = 0.02) chemotherapy alone. In HR-negative (HR-) cancers, there were no significant differences in the rate of pathologic response (pCR/RCB-I) from 3-wP/FAC (50%), wP/FAC (68%), or concurrent H + 3-wP/FEC (72%).

CONCLUSIONS

Patients with HR+/HER2+ breast cancer obtained significant benefit from addition of trastuzumab to P/FEC chemotherapy; pathologic response rate was similar to that seen in HR-/HER2+ breast cancers.