Tumor mutational burden is not predictive of cytotoxic chemotherapy response

Figures & data

Table 1. Demographics for 294 subjects who initiated chemotherapy within 1 year of TMB.

	Median (Range)
Age (years)	60 (22–86)
Tumor mutational burden (mutations/megabase)	5 (1–347)
	N (%)
Gender
Male	142 (48%)
Female	152 (52%)
Cancer Type
Breast	40 (14%)
Lung	47 (16%)
Gastrointestinal	100 (34%)
Other	107 (36%)
Types of Chemotherapy (N)
Carboplatin	86
5-fluorouracil	81
Paclitaxel	54
Gemcitabine	49
Oxalipatin	42
Cisplatin	35
Clinical benefit*
Complete response	11 (4%)
Partial response	137 (48%)
Stable disease≥6 months	36 (13%)
Stable disease< 6 months	24 (8%)
Progressive Disease	76 (27%)

*Patients with stable disease who were censored prior to 6 months of therapy were excluded from the clinical benefit analysis

Figure 1. Consort diagram for study.

Figure 2. Tumor mutational burden vs. SD≥6 months/PR/CR. Data represent the median and 25–75% interquartile range for tumor mutational burden. Patients with SD≥6 months/PR/CR after chemotherapy had similar tumor mutational burden to those with progression disease (PD) or SD<6 months (median (25–75%): 5 (3–7.5) vs. 5 (2–8) mutations/megabase; p = .22). Patients with stable disease who were censored prior to 6 months of evaluation were excluded from the analysis.

Figure 3. Kaplan Meier survival analysis. Progression-free survival for patients with tumor mutational burden of 10 or greater is similar to those with TMB less than 10 (p = .21).

Table

IRB	institutional review board
UCSD-PREDICT	University of California San Diego Study of Personalized Cancer Therapy to Determine Response and Toxicity
Mb	Megabase
TMB	tumor mutational burden