“…This data set, reported by Efron (1988), represents the survival times (in days) of a group of 44 patients suffering from Head and Neck cancer (HNC) disease and treated using a combination of radiotherapy and chemotherapy (RT+CT). The ordered data times are: 12.2, 23.56, 23.74, 25.87, 31.98, 37, 41.35, 47.38, 55.46, 58.36, 63.47, 68.46, 74.47, 78.26, 81.43, 84, 92, 94, 110, 112, 119, 127, 130, 133, 140, 146, 155, 159, 173, 179, 194, 195, 209, 249, 281, 319, 339, 432, 469, 519, 633, 725, 817, 1776. Recently, this data set was also analyzed by several authors, e.g., see Sharma et al (2015), Sharma (2018) and Vishwakarma et al (2018). First, we fit the GCD to the complete data set along ten popular lifetime distributions as its competitors, namely: CD, Gompertz distribution (GD), Hjorth distribution (HD), Weibull distribution (WD), generalized Pareto distribution (GPD), exponentiated Pareto distribution (EPD), generalized-exponential distribution (GED), generalized Rayleigh distribution (GRD), generalized half-logistic distribution (GHLD) and Nadarajah-Haghighi distribution (NHD) with their respective PDFs (for x > 0 and α, β, λ > 0), see Table 11.…”