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. Author manuscript; available in PMC: 2014 May 15.
Published in final edited form as: Cancer. 2013 Feb 13;119(10):1900–1907. doi: 10.1002/cncr.27968

Table 2.

Detailed Calculation of Observed-to-Expected Ratio

Cancer sites Column A Column B Column C Column D O/E ratio
(column A ÷
column D)		 Z-score*
Eight-year
cumulative
observed
number of
cancer-specific
deaths
documented
within SEER		 Eight -year
cumulative
observed
number of
overall deaths
that SEER
documented		 Eight -year
cumulative
expected
number of
overall
deaths as
estimated by
US life tables		 Eight-year
cumulative
expected
number of
deaths
attributed
to the
malignancy
(column B -
column C)
Breast (stage II-
IV)		 23,216 33,133 9,409 23,724 0.97 3.95
Colorectal 39,973 60,052 19,298 40,754 0.98 5.09
Lung 79,535 94,182 6,732 87,450 0.90 70.1
Melanoma 4,045 7,197 3,446 3,751 1.07 5.12
Prostate (stage
IV)		 10,092 19,198 9,400 9,798 1.02 4.29
Pancreas 14,322 16,436 945 15,491 0.92 39.1

Abbreviations: SEER, Surveillance Epidemiology and End Results

*

Z-score> 1.96, p-value< 0.05; Z-score> 2.58, p-value< 0.01; Z-score> 3.29, p-value< 0.001