Somatic mutation profiling and associations with prognosis and trastuzumab benefit in early breast cancer

Sherene Loi, Stefan Michiels, Diether Lambrechts, Debora Fumagalli, Bart Claes, Pirkko-Liisa Kellokumpu-Lehtinen, Petri Bono, Vesa Kataja, Martine J Piccart, Heikki Joensuu, Christos Sotiriou, Sherene Loi, Stefan Michiels, Diether Lambrechts, Debora Fumagalli, Bart Claes, Pirkko-Liisa Kellokumpu-Lehtinen, Petri Bono, Vesa Kataja, Martine J Piccart, Heikki Joensuu, Christos Sotiriou

Abstract

Background: Certain somatic alterations in breast cancer can define prognosis and response to therapy. This study investigated the frequencies, prognostic effects, and predictive effects of known cancer somatic mutations using a randomized, adjuvant, phase III clinical trial dataset.

Methods: The FinHER trial was a phase III, randomized adjuvant breast cancer trial involving 1010 women. Patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer were further randomized to 9 weeks of trastuzumab or no trastuzumab. Seven hundred five of 1010 tumors had sufficient DNA for genotyping of 70 somatic hotspot mutations in 20 genes using mass spectrometry. Distant disease-free survival (DDFS), overall survival (OS), and interactions with trastuzumab were explored with Kaplan-Meier and Cox regression analyses. All statistical tests were two-sided.

Results: Median follow-up was 62 months. Of 705 tumors, 687 were successfully genotyped. PIK3CA mutations (exons 1, 2, 4, 9, 13, 18, and 20) were present in 25.3% (174 of 687) and TP53 mutations in 10.2% (70 of 687). Few other mutations were found: three ERBB2 and single cases of KRAS, ALK, STK11/LKB1, and AKT2. PIK3CA mutations were associated with estrogen receptor positivity (P < .001) and the luminal-A phenotype (P = .04) but were not statistically significantly associated with prognosis (DDFS: hazard ratio [HR] = 0.88, 95% confidence [CI] = 0.58 to 1.34, P = .56; OS: HR = 0.603, 95% CI = .32 to 1.13, P = .11), although a statistically significant nonproportional prognostic effect was observed for DDFS (P = .002). PIK3CA mutations were not statistically significantly associated with trastuzumab benefit (P(interaction): DDFS P = .14; OS P = .24).

Conclusions: In this dataset, targeted genotyping revealed only two alterations at a frequency greater than 10%, with other mutations observed infrequently. PIK3CA mutations were associated with a better outcome, however this effect disappeared after 3 years. There were no statistically significant associations with trastuzumab benefit.

Figures

Figure 1.
Figure 1.
Frequency and associations between mutations. Absolute numbers are shown of PIK3CA mutant, PIK3CA wild type, ERBB2 mutant, and TP53 mutant, as well as those tumors with coexisting mutations. PIK3CA exon 9 and 20 mutations (and other locations) are also shown.
Figure 2.
Figure 2.
Prognostic associations between patients who had a PIK3CA mutation (mt) vs wild type (WT) and clinical outcome. A–C) Kaplan-Meier plots of the cumulative proportion of patients surviving with the time in years. Various clinical end points are shown: distant disease-free survival (A), recurrence-free survival (B), and overall survival (C). Cox regression hazard ratios (HRs) and 95% confidence intervals (CIs) are shown, stratified by chemotherapy type given. All statistical tests are two-sided. The number of patients at risk in each group is given below the graphs.
Figure 3.
Figure 3.
Prognostic associations between PIK3CA genotype and clinical outcome according to mutation location on the gene (helical/exon 9 vs kinase/exon 20 domain). The number of patients at risk in each group is given below the graphs. A–C) Kaplan-Meier plots of the cumulative proportion of patients surviving with the time in years. Various clinical end points are shown: distant disease-free survival (A), recurrence-free survival (B), and overall survival (C). The two patients with dual mutations were excluded and all treatment arms were pooled. P values correspond to log-rank tests; mt = mutant; WT = wild type. All statistical tests are two-sided.
Figure 4.
Figure 4.
Interaction between PIK3CA genotype and trastuzumab efficacy. A) Kaplan-Meier plots comparing trastuzumab vs no trastuzumab treatment arms for PIK3CA mutated (mt), HER2-positive cohorts. Cumulative proportions of patients surviving distant disease free are shown. B) Kaplan-Meier plots comparing trastuzumab vs no trastuzumab for PIK3CA wild-type (WT), HER2-positive cohorts. Cumulative proportions of patients surviving distant disease free are shown. C) Interaction forest plots indicate Cox regression hazard ratios (HRs) and 95% confidence intervals (CIs) stratified by chemotherapy type given for trastuzumab benefit for distant disease-free survival (DDFS). according to PIK3CA genotype and by overall series. D) Kaplan-Meier plots comparing trastuzumab vs no trastuzumab treatment arms for PIK3CA mt, HER2-positive cohorts. Cumulative proportions of patients surviving relapse free are shown. E) Kaplan-Meier plots comparing trastuzumab vs no trastuzumab treatment arms for PIK3CA WT, HER2-positive cohorts. Cumulative proportions of patients surviving relapse free are shown. F) Interaction forest plots indicate Cox regression HRs and 95% CIs stratified by chemotherapy type given for trastuzumab benefit for recurrence-free survival (RFS) according to PIK3CA genotype and by overall series. G) Kaplan-Meier plots comparing trastuzumab vs no trastuzumab treatment arms for PIK3CA mt, HER2-positive cohorts. Cumulative proportions of patients alive are shown. H) Kaplan-Meier plots comparing trastuzumab vs no trastuzumab treatment arms for PIK3CA WT, HER2-positive cohorts. Cumulative proportions of patients alive are shown. I) Interaction forest plots indicate Cox regression HRs and 95% CIs stratified by chemotherapy type given for trastuzumab benefit for overall survival. according to PIK3CA genotype and by overall series. All statistical tests are two-sided. The number of patients at risk in each group is given below the graphs.

References

    1. Perou CM, Sorlie T, Eisen MB, et al. Molecular portraits of human breast tumours. Nature. 2000;406(6797):747–752.
    1. Slamon DJ, Clark GM, Wong SG, et al. Human breast cancer: correlation of relapse and survival with amplification of the HER-2/neu oncogene. Science. 1987;235(4785):177–182.
    1. Engelman JA. Targeting PI3K signalling in cancer: opportunities, challenges and limitations. Nat Rev Cancer. 2009;9(8):550–562.
    1. Cizkova M, Susini A, Vacher S, et al. PIK3CA mutation impact on survival in breast cancer patients and in ERalpha, PR and ERBB2-based subgroups. Breast Cancer Res. 2012;14(1):R28.
    1. Kalinsky K, Jacks LM, Heguy A, et al. PIK3CA mutation associates with improved outcome in breast cancer. Clin Cancer Res. 2009;15(16):5049–5059.
    1. Loi S, Haibe-Kains B, Majjaj S, et al. PIK3CA mutations associated with gene signature of low mTORC1 signaling and better outcomes in estrogen receptor-positive breast cancer. Proc Natl Acad Sci U S A. 2010;107(22):10208–10213.
    1. Stemke-Hale K, Gonzalez-Angulo AM, Lluch A, et al. An integrative genomic and proteomic analysis of PIK3CA, PTEN, and AKT mutations in breast cancer. Cancer Res. 2008;68(15):6084–6091.
    1. Isakoff SJ, Engelman JA, Irie HY, et al. Breast cancer-associated PIK3CA mutations are oncogenic in mammary epithelial cells. Cancer Res. 2005;65(23):10992–11000.
    1. Zhao JJ, Liu Z, Wang L, et al. The oncogenic properties of mutant p110alpha and p110beta phosphatidylinositol 3-kinases in human mammary epithelial cells. Proc Natl Acad Sci U S A. 2005;102(51):18443–18448.
    1. Perez-Tenorio G, Alkhori L, Olsson B, et al. PIK3CA mutations and PTEN loss correlate with similar prognostic factors and are not mutually exclusive in breast cancer. Clin Cancer Res. 2007;13(12):3577–3584.
    1. Baselga J, Semiglazov V, van Dam P, et al. Phase II randomized study of neoadjuvant everolimus plus letrozole compared with placebo plus letrozole in patients with estrogen receptor-positive breast cancer. J Clin Oncol. 2009;27(16):2630–2637.
    1. Ellis MJ, Lin L, Crowder R, et al. Phosphatidyl-inositol-3-kinase alpha catalytic subunit mutation and response to neoadjuvant endocrine therapy for estrogen receptor positive breast cancer. Breast Cancer Res Treat. 2010;119(2):379–390.
    1. Berns K, Horlings HM, Hennessy BT, et al. A functional genetic approach identifies the PI3K pathway as a major determinant of trastuzumab resistance in breast cancer. Cancer Cell. 2007;12(4):395–402.
    1. Junttila TT, Akita RW, Parsons K, et al. Ligand-independent HER2/HER3/PI3K complex is disrupted by trastuzumab and is effectively inhibited by the PI3K inhibitor GDC-0941. Cancer. Cell. 2009;15(5):429–440.
    1. Serra V, Markman B, Scaltriti M, et al. NVP-BEZ235, a dual PI3K/mTOR inhibitor, prevents PI3K signaling and inhibits the growth of cancer cells with activating PI3K mutations. Cancer Res. 2008;68(19):8022–8030.
    1. Baselga J, Bradbury I, Eidtmann H, et al. Lapatinib with trastuzumab for HER2-positive early breast cancer (NeoALTTO): a randomised, open-label, multicentre, phase 3 trial. Lancet. 2012;379(9816):633–640.
    1. Baselga J, Cortes J, Kim SB, et al. Pertuzumab plus trastuzumab plus docetaxel for metastatic breast cancer. N Engl J Med. 2011;366(2):109–119.
    1. Gianni L, Pienkowski T, Im YH, et al. Efficacy and safety of neoadjuvant pertuzumab and trastuzumab in women with locally advanced, inflammatory, or early HER2-positive breast cancer (NeoSphere): a randomised multicentre, open-label, phase 2 trial. Lancet Oncol. 2011;13(1):25–32.
    1. Simon RM, Paik S, Hayes DF. Use of archived specimens in evaluation of prognostic and predictive biomarkers. J Natl Cancer Inst. 2009;101(21):1446–1452.
    1. McShane LM, Altman DG, Sauerbrei W, et al. Reporting recommendations for tumor marker prognostic studies (REMARK). J Natl Cancer Inst. 2005;97(16):1180–1184.
    1. Joensuu H, Bono P, Kataja V, et al. Fluorouracil, epirubicin, and cyclophosphamide with either docetaxel or vinorelbine, with or without trastuzumab, as adjuvant treatments of breast cancer: final results of the FinHer Trial. J Clin Oncol. 2009;27(34):5685–5692.
    1. Joensuu H, Kellokumpu-Lehtinen PL, Bono P, et al. Adjuvant docetaxel or vinorelbine with or without trastuzumab for breast cancer. N Engl J Med. 2006;354(8):809–820.
    1. Miller SA, Dykes DD, Polesky HF. A simple salting out procedure for extracting DNA from human nucleated cells. Nucleic Acids Res. 1988;16(3):1215.
    1. Welcome Trust Sanger Institute. Catalogue of somatic mutations in cancer. Accessed August 2011.
    1. De Roock W, Claes B, Bernasconi D, et al. Effects of KRAS, BRAF, NRAS, and PIK3CA mutations on the efficacy of cetuximab plus chemotherapy in chemotherapy-refractory metastatic colorectal cancer: a retrospective consortium analysis. Lancet Oncol. 2010;11(8):753–762.
    1. MacConaill LE, Campbell CD, Kehoe SM, et al. Profiling critical cancer gene mutations in clinical tumor samples. PLoS One. 2009;4(11):e7887.
    1. Grambsch PM, Therneau TM. Proportional hazards tests and diagnostics based weighted residuals. Biometrika. 1994;81(3):515–526.
    1. Cheang MC, Chia SK, Voduc D, et al. Ki67 index, HER2 status, and prognosis of patients with luminal B breast cancer. J Natl Cancer Inst. 2009;101(10):736–750.
    1. Jensen JD, Knoop A, Laenkholm AV, et al. PIK3CA mutations, PTEN, and pHER2 expression and impact on outcome in HER2-positive early-stage breast cancer patients treated with adjuvant chemotherapy and trastuzumab. Ann Oncol. 2012;23(8)2034–2042.
    1. Oda K, Okada J, Timmerman L, et al. PIK3CA cooperates with other phosphatidylinositol 3’-kinase pathway mutations to effect oncogenic transformation. Cancer Res. 2008;68(19):8127–8136.
    1. Park S, Jiang Z, Mortenson ED, et al. The therapeutic effect of anti-HER2/neu antibody depends on both innate and adaptive immunity. Cancer Cell. 2010;18(2):160–170.
    1. Clynes RA, Towers TL, Presta LG, et al. Inhibitory Fc receptors modulate in vivo cytoxicity against tumor targets. Nat Med. 2000;6(4):443–446.
    1. Stagg J, Loi S, Divisekera U, et al. Anti-ErbB-2 mAb therapy requires type I and II interferons and synergizes with anti-PD-1 or anti-CD137 mAb therapy. Proc Natl Acad Sci U S A. 2011;108(17):7142–7147.
    1. Dituri F, Mazzocca A, Giannelli G, et al. PI3K functions in cancer progression, anticancer immunity and immune evasion by tumors. Clin Dev Immunol. 2011;2011 947858.
    1. Wang Y, Zhou D, Phung S, et al. SGK3 Is an estrogen-inducible kinase promoting estrogen-mediated survival of breast cancer cells. Mol Endocrinol. 2011;25(1):72–82.
    1. Vasudevan KM, Barbie DA, Davies MA, et al. AKT-independent signaling downstream of oncogenic PIK3CA mutations in human cancer. Cancer Cell. 2009;16(1):21–32.
    1. TCGA. Comprehensive molecular portraits of human breast tumours. Nature. 2012;490(7418):61–70.
    1. Frasor J, Danes JM, Komm B, et al. Profiling of estrogen up- and down-regulated gene expression in human breast cancer cells: insights into gene networks and pathways underlying estrogenic control of proliferation and cell phenotype. Endocrinology. 2003;144(10):4562–4574.
    1. Yarden RI, Wilson MA, Chrysogelos SA. Estrogen suppression of EGFR expression in breast cancer cells: a possible mechanism to modulate growth. J Cell Biochem. 2001;81(S36):232–246.
    1. Carracedo A, Alimonti A, Pandolfi PP. PTEN level in tumor suppression: how much is too little? Cancer Res. 2011;71(3):629–633.
    1. Yuan TL, Cantley LC. PI3K pathway alterations in cancer: variations on a theme. Oncogene. 2008;27(41):5497–5510.
    1. Ellis MJ, Ding L, Shen D, et al. Whole-genome analysis informs breast cancer response to aromatase inhibition. Nature. 2012;486(7403):353–360.
    1. Stephens PJ, Tarpey P, Davies HR, et al. The landscape of cancer genes and mutational processes in breast cancer. Nature. 2012;486(7403):400–404.
    1. Brachmann SM, Hofmann I, Schnell C, et al. Specific apoptosis induction by the dual PI3K/mTor inhibitor NVP-BEZ235 in HER2 amplified and PIK3CA mutant breast cancer cells. Proc Natl Acad Sci U S A. 2009;106(52):22299–22304.
    1. O’Brien C, Wallin JJ, Sampath D, et al. Predictive biomarkers of sensitivity to the phosphatidylinositol 3′ kinase inhibitor GDC-0941 in breast cancer preclinical models. Clin Cancer Res. 2010;16(14):3670–3683.
    1. Weigelt B, Warne PH, Downward J. PIK3CA mutation, but not PTEN loss of function, determines the sensitivity of breast cancer cells to mTOR inhibitory drugs. Oncogene. 2010;30(29):3222–3233.
    1. Banerji S, Cibulskis K, Rangel-Escareno C, et al. Sequence analysis of mutations and translocations across breast cancer subtypes. Nature. 2012;486(7403):405–409.
    1. Shah SP, Roth A, Goya R, et al. The clonal and mutational evolution spectrum of primary triple-negative breast cancers. Nature. 2012;486(7403):395–399.
    1. Lee JW, Soung YH, Seo SH, et al. Somatic mutations of ERBB2 kinase domain in gastric, colorectal, and breast carcinomas. Clin Cancer Res. 2006;12(1):57–61.
    1. Kancha RK, von Bubnoff N, Bartosch N, et al. Differential sensitivity of ERBB2 kinase domain mutations towards lapatinib. PLoS One. 2011;6(10):e26760.
    1. Trowe T, Boukouvala S, Calkins K, et al. EXEL-7647 inhibits mutant forms of ErbB2 associated with lapatinib resistance and neoplastic transformation. Clin Cancer Res. 2008;14(8):2465–2475.
    1. Bose R, Kavuri SM, Searleman AC, et al. Activating HER2 mutations in HER2 gene amplification negative breast cancer. Cancer Discov. 2013;3(2):224–237.
    1. Gerlinger M, Rowan AJ, Horswell S, et al. Intratumor heterogeneity and branched evolution revealed by multiregion sequencing. N Engl J Med. 2012;366(10):883–892.

Source: PubMed

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