Abstract 5884
Background
The era of immunotherapy changed considerably prognosis of melanoma. Nonetheless, only around 40% can get benefit from this treatment, with no biomarkers identified for the therapeutic choice. On the basis of emerging clinical evidence, increased Tumor Mutational Burden (TMB) may be associated with higher sensitivity to immunotherapeutic agents.
Methods
The aim of this study was to analyze in advanced melanoma the relationship between the mutation load and: i) the histologic characteristics, ii) locations according to sun exposure and iii) response to PD-1 inhibitors, in advanced melanoma patients, in a retrospective multicentric analysis by sequencing using FoundationOne®. TMB was characterized as the number of somatic protein-coding base substitution or alterations mutations per megabase (Mb). DNA was extracted from paraffin embedded sections of primary tumor or metastasis. TMB was considered low between 1 and 5 muts/Mb, intermediate between 6 and 19, high if > 20 muts/Mb.
Results
In five centers in France, we included between October 2017 and March 2019 101 patients, aged from 16-year to 92-year-old, with metastatic melanomas. Results were available for 89 cases (12% DNA extraction failure). Acral (n = 6, 20%), mucosal (n = 5, 17%) and uveal melanoma (n = 4, 13%) had a lower TMB compared to sun-exposed melanomas. No melanoma of non-sun-exposed areas had high burden (n = 0); intermediate TMB was found in 21% (n = 8) and low TMB in 63% of cases (n = 19). Conversely, melanoma on chronic exposed areas (face and neck) had high TMB (5/7 cases; 71%). Complete and partial remission after 3 months of anti-PD-1 were more often observed in TMB high patients (n = 4;20%) whereas in low and intermediate mutational patients, progression was found in respectively 62% (n = 24) and 53% (n = 16).
Conclusions
TMB is affected by a variety of causes, including ultraviolet light in melanoma and smoking in lung cancer. Desmoplastic melanomas have been reported to have a high prevalence of somatic mutations whereas mucosal and acral have a 5-to 10-fold lower. Our study highlights the importance of TMB with higher response to PD-1 blockade. While it has to be confirmed, sun exposed areas or UV-signature may in be a valuable criterion in helping clinical decision-making.
Clinical trial identification
Editorial acknowledgement
Foundation One Medicine and Roche Laboratories.
Legal entity responsible for the study
French hospitals.
Funding
Has not received any funding.
Disclosure
C. Allayous: Travel / Accommodation / Expenses: BMS; Travel / Accommodation / Expenses: Roche; Travel / Accommodation / Expenses: Amgen. All other authors have declared no conflicts of interest.
Resources from the same session
5520 - Patient’s Usability Test results of a CINV Diary Application For Smartphones
Presenter: Paz Fernandez
Session: Poster Display session 3
Resources:
Abstract
2323 - Colorectal Telephone Assessment Pathway (CTAP) - A viable means of shortening time to a definitive diagnosis of Colorectal Cancer (CRC)
Presenter: Harriet Watson
Session: Poster Display session 3
Resources:
Abstract
6119 - Cancer Nursing and Social Media: Capturing the Zeitgeist
Presenter: Mark Foulkes
Session: Poster Display session 3
Resources:
Abstract
1776 - Examination of mobile applications on breast cancer
Presenter: AYDANUR AYDIN
Session: Poster Display session 3
Resources:
Abstract
4128 - E-health effectiveness to increase patient adherence for immunotherapy; a cost-benefit study.
Presenter: Maria José Dias
Session: Poster Display session 3
Resources:
Abstract
3219 - Experiences of internet-based stepped care among individuals with recently diagnosed cancer and symptoms of anxiety and/or depression
Presenter: Anna Hauffman
Session: Poster Display session 3
Resources:
Abstract
5010 - What do cancer patients know about their immunotherapy treatment?
Presenter: Mónica Arellano
Session: Poster Display session 3
Resources:
Abstract
4503 - Prospective Comparison of Travel Burden, Cost and Time to Obtain Tumor Board Treatment Plan Through In-Person Visits vs. an AI Enabled Health Technology (N=1803)
Presenter: Rajendra Badwe
Session: Poster Display session 3
Resources:
Abstract
4123 - Cancer care through the fire and flames: 3-year experience in the utilisation of electronic consultation and referral system at the Red Zone in Southern Thailand
Presenter: Nanthiya Rattanakhot
Session: Poster Display session 3
Resources:
Abstract
2087 - The effect of e-mobile education on the quality of life in women with breast cancer
Presenter: Derya ÇInar
Session: Poster Display session 3
Resources:
Abstract