TABLE A3. 



ANALYSIS OF PRIMARY TUMORS IN MALE RATS IN THE TWO-YEAR FEED STUDY 

 OF NITROFURANTOIN (Continued) 



Control 



1,300 ppm 



2,500 ppm 



Thyroid Gland: Follicular Cell Adenoma or Carcinoma 



Overall Rates (a) 



Adjusted Rates (b) 



Terminal Rates (c) 



Day of First Observation 



Life Table Tests (d) 



Logistic Regression Tests (d) 



Cochran-Armitage Trend Test (d ) 



Fisher Exact Test(d) 



Hematopoietic System: Mononuclear Leukemia 



Overall Rates (a) 



Adjusted Rates (b) 



Terminal Rates (c) 



Day of First Observation 



Life Table Tests (d) 



Logistic Regression Tests (d) 



CochranArmitage Trend Test (d) 



Fisher Exact Test (d) 



All Sites: Malignant Mesothelioma 



Overall Rates (a) 



Adjusted Rates (b) 



Terminal Rates (c) 



Day of First Observation 



Life Table Tests (d) 



Logistic Regression Tests (d ) 



CochranArmitage Trend Test (d) 



Fisher Exact Test (d) 



All Sites: All Mesothelioma 



Overall Rates (a) 



Adjusted Rates (b) 



Terminal Rates (c) 



Day of First Observation 



Life Table Tests (d) 



Logistic Regression Tests (d) 



CochranArmitage Trend Test (d) 



Fisher Exact Test (d) 



(a I Number of tumor-bearing animals/number of animals examined at the site 



(b) Kaplan-Meier estimated tumor incidences at the end of the study after adjusting for intercurrent mortality 



(c) Observed tumor incidence at terminal kill 



(d) Beneath the control incidence are the P values associated with the trend test. Beneath the dosed group incidence are the 

 P values corresponding to pairwise comparisons between that dosed group and the controls. The life table analysis regards tu- 

 mors in animals dying prior to terminal kill as being (directly or indirectly) the cause of death. The logistic regression test re- 

 gards these lesions as nonfatal. The CochranArmitage and Fisher exact tests compare directly the overall incidence rates. 

 A negative trend or lower incidence in a dosed group is indicated by (N). 



(e) No P value is reported because no tumors were observed in the 2,500-ppm and control groups. 



Nitrofurantoin, NTP TR 341 



98 



