TABLE 1.

Abundance estimates of intratumoral bacteria among seven major human cancers profiled by Nejman et al. (Ravid Straussman, personal communication).^[57] One thousand iteration-bootstraps of the mean and median approximated the average number of bacteria per 40 nanograms of DNA on a per-cancer and pan-cancer basis. Conversions and assumptions of tumor ploidy, purity, and homogeneity are detailed in Box 1. Area density estimates assume 5200 total cells/mm² and volume density estimates assume 10⁹ total cells/cm³. In the two far-right columns, “med.” denotes the propagated “median” bootstrapped value and “avg.” denotes the propagated “average” bootstrapped value.

Cancer type in Nejman et al. 2020[57]	qPCR sample size (n)	Absolute range (bacteria/40ng) (min, max)	Bootstrapped estimate of median bacteria per 40 ng DNA (median, 95% CI; 1000 iterations)	Bootstrapped estimate of average bacteria per 40 ng DNA (mean, 95% CI; 1000 iterations)	Area density estimate (bacteria/mm2)	Volume density estimate (bacteria/cm3)
Melanoma	200	(0.85, 3023)	6.72 (5.99, 7.77)	31.69 (9.71, 71.20)	~7 med., ~33 avg.	~1.3×106 med., ~6.3×106 avg.
Lung	274	(1.2, 3663)	5.83 (5.13, 6.48)	22.50 (7.90, 50.35)	~6 med., ~23 avg.	~1.2×106 med., ~4.5×106 avg.
Ovarian	57	(1.84, 73.2)	9.88 (7.59, 12.37)	12.72 (10.25, 16.00)	~10 med., ~13 avg.	~2.0×106 med., ~2.5×106 avg.
GBM	37	(3.41, 77.4)	10.06 (6.62, 15.85)	15.55 (10.89, 20.85)	~10 med., ~16 avg.	~2.0×106 med., ~3.1×106 avg.
Pancreatic	66	(3.82, 2147)	17.17 (11.72, 22.36)	70.43 (26.19, 147.78)	~18 med., ~73 avg.	~3.4×106 med., ~14×106 avg.
Bone	30	(1.62, 76.4)	15.53 (12.78, 18.53)	19.33 (13.97, 25.51)	~16 med., ~20 avg.	~3.1×106 med., ~3.9×106 avg.
Breast	352	(0.765, 1723)	14.82 (13.35, 16.39)	44.63 (31.41, 59.83)	~15 med., ~46 avg.	~3.0×106 med., ~8.9×106 avg.
Pan-cancer	1016	(0.765, 3663)	9.15 (8.70, 9.60)	34.19 (24.04, 46.56)	~10 med., ~35 avg.	~1.8×106 med., ~6.8×106 avg.