Registration Dossier

Toxicological information

Carcinogenicity

Currently viewing:

Administrative data

Description of key information

Key study. Carcinogenicity study (24 years) in monkeys (non-GLP). The test item at a dose of 25 mg/kg bw/d did not produce any adverse effect administered in the diet of three species of monkeys beginning at birth and continuing for nearly the entire lifetime of the animals. Therefore, the test item is deemed non-carcinogenic.

Key value for chemical safety assessment

Carcinogenicity: via oral route

Link to relevant study records
Reference
Endpoint:
carcinogenicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1970-1995
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Qualifier:
no guideline followed
GLP compliance:
not specified
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Fisher Scientific Company.
Species:
monkey
Strain:
other: Macaca fascicularis (cynomolgus), Macaca mulatta (rhesus), and Cercopithecus aethiops (African green).
Details on species / strain selection:
Monkeys were selected at the time of inception of this study in 1970 from those available in a monkey colony consisting of three species. A total of 20 monkeys were treated. They included 6 African green, 7 rhesus, 6 cynomolgus, and 1 hybrid rhesus male × cynomolgus female monkey.
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 24h
- Diet: The animals were given a diet consisting of high-protein Purina monkey chow (5045 Standard), with a vitamin spread on sandwiches and apples.
- Water: ad libitum.

ENVIRONMENTAL CONDITIONS
The monkeys were cared for according to the standards established by the Association for Assessment and Accreditation for Laboratory Animal Care (AAALAC). The experimental protocols used were approved by the Animal Sciences Branch of the National Cancer Institute and reviewed on an annual basis.
Route of administration:
oral: feed
Details on exposure:
DIET PREPARATION
- For newborn monkeys, sodium saccharin was added to the Similac formula at the time of feeding.
- When the monkeys were 6 months old, the compound was incorporated into a vitamin mixture that was given to the monkeys as a vitamin sandwich on a slice of bread. The mixture consisted of powdered dry milk (5 pounds), Parvo (a folic acid supplement, 4 ounces, 20% with starch; Roche Agricultural Products), Cecon (a vitamin C supplement, 300 mL; Abbott Laboratories, Chicago, IL), molasses (2 L), and water (500 mL). The vitamin mixture was spread onto bread (1 teaspoon per slice of bread), after which the dose of sodium saccharin was added on top of the spread and the bread was folded in half to form a sandwich and then fed to the animal.
Analytical verification of doses or concentrations:
no
Remarks:
not required.
Duration of treatment / exposure:
24 years: test item administration was initiated within 24 hours after birth and was continued until the animals died or were euthanized at the end of the study.
Frequency of treatment:
5 days a week
Dose / conc.:
25 mg/kg bw/day (nominal)
Control animals:
yes, concurrent no treatment
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Use of 10 times the allowable daily intake was the standard choice of dose for the National Cancer Institute’s nonhuman primate carcinogenicity testing program at the time of inception of this study.
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: No data

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: The individual monkeys underwent complete physical examinations by a veterinarian every 6 months.

BODY WEIGHT: Yes / No / No data
- Time schedule for examinations:

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data

OPHTHALMOSCOPIC EXAMINATION: No / No data

HAEMATOLOGY / CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: the following routine blood examinations were performed at intervals of 3–6 months: hematocrit, hemoglobin, white blood cell count, platelet count, and other clinical parameters (i.e., alkaline phosphatase, total bilirubin, serum glutamic pyruvic transaminase, and serum glutamic oxalacetic transaminase).
- Anaesthetic used for blood collection: Yes (identity) / No / No data
- Animals fasted: Yes / No / No data
- How many animals: 20

URINALYSIS: Yes
- Time schedule for collection of urine: One to 2 years before the animals were euthanized, urine samples were collected from two male and two female monkeys that had been treated with sodium saccharin and from two male and two female controls of the cynomolgus and the rhesus species. Collection was from 8 AM to 10 AM.
- Animals fasted: Yes
- Parameters: Urinary pH was determined by use of the Beckman combination electrode (Beckman Instruments, Inc., Fullerton, CA), and urine chemistries were determined on an Ektachem 700 Chemistry Analyzer (Eastman Kodak Co., Rochester, NY), except for chloride determinations, which were measured on an Astra 4 Automated Analyzer (Beckman Instruments, Inc.), and protein determinations, which were measured by use of
the Bradford protein assay (BioRad Laboratories, Richmond, CA). The urine samples were examined for solid material by means of scanning electron microscopy. A sample of fresh-voided control urine was also collected and examined by for the potential of sodium saccharin to associate (coelute) with urinary macromolecules. Urinary filters were examined by means of scanning electron microscopy (Phillips 515 Scanning Electron Microscope; Phillips, Inc., Eindhoven, The Netherlands) with attached energy dispersive spectroscopy (Kevex Micro-X 7000 Analytical Spectrometer with Quant-X Program; Kevex, Inc., Hayward, CA).

NEUROBEHAVIOURAL EXAMINATION: No / No data
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
- Monkeys that died or were euthanized were carefully necropsied. Animals remaining for the terminal euthanasia were put under deep anesthesia.

HISTOPATHOLOGY: Yes
- The following tissues and organs were fixed in buffered formalin: brain, pituitary, salivary gland, thyroid, tongue, cheek pouches, trachea, esophagus, lungs, heart, aorta, liver, gallbladder, spleen, kidneys, adrenals, stomach, pancreas, duodenum, jejunum, ileum, large intestine, lymph nodes, urinary bladder, testis, prostate, seminal vesicles (or ovaries and uterus), breast, skin, and bone marrow, as well as any grossly apparent tumor tissue. Tissue sections were routinely processed for paraffin embedding and stained with hematoxylin–eosin.
Clinical signs:
no effects observed
Dermal irritation (if dermal study):
not examined
Mortality:
mortality observed, non-treatment-related
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Description (incidence and severity):
No serum, hematologic, or chemical abnormalities were detected in these animals during their lifetime.
Clinical biochemistry findings:
no effects observed
Description (incidence and severity):
No serum, hematologic, or chemical abnormalities were detected in these animals during their lifetime.
Urinalysis findings:
no effects observed
Description (incidence and severity):
Measurement of urine chemistries showed no differences between treated monkeys and controls.
Behaviour (functional findings):
no effects observed
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
effects observed, non-treatment-related
Description (incidence and severity):
- Group 1: The most frequent histopathologic findings at necropsy of these monkeys involved the respiratory system. Five of these monkeys were found at necropsy to have lung infection, edema, congestion, or atelectasis. In one monkey, acute bronchial aspiration and pneumonia were present. In two monkeys, there was myocardial fibrosis associated with myocardial fatty degeneration. One monkey had chronic ulcers of the stomach and esophagus, and another monkey had histologically observed chronic ileitis. None of these monkeys had abnormalities of the urothelium, including the renal pelvis, ureters, urinary bladder, or urethra.
- Group 2: three of the 12 monkeys had myocardial fibrosis and three had myocardial fatty degeneration. In seven of these 12 monkeys, fatty degeneration of the liver was noted, and one animal had a liver cyst. Light microscopy showed no evidence in any of these monkeys of urothelial changes, i.e., in the renal pelvis, the ureters, the urinary bladder, or the urethra. No abnormalities were seen in the urinary bladders of the 12 treated monkeys and the six control monkeys examined by scanning electron microscopy following glutaraldehyde fixation.
Histopathological findings: neoplastic:
effects observed, non-treatment-related
Description (incidence and severity):
- Group 2: Histologic examination revealed a thyroid lymphoma in the first monkey, leiomyoma of the uterus in the second monkey, and a papillary
cystadenoma of the ovary and leiomyoma of the stomach in the third monkey. The lesions observed in age-matched control monkeys showed myocardial
and hepatocellular changes similar to those observed in the treated animals, but no definite tumors were seen. It should be noted that the three types of tumors found in the saccharin-treated monkeys have also been observed in breeders and normal controls in this monkey colony
Other effects:
no effects observed
Based on:
test mat.
Sex:
male/female
Remarks on result:
not determinable due to absence of adverse toxic effects
Key result
Critical effects observed:
no

Table 1. Tumors and other lesions in monkeys treated with sodium saccharin

Animal No.

Species*

               Age at  Month

Sex†     first dose           dosed  Total dose, g     Major autopsy findings

 

 

Group 1: monkeys that died during the course of the experiment from non-neoplastic diseases

827K

Rh

M

2 days

103

267.8

Bronchial aspiration

1206S

Cy

F

2 days

128

229.9

Bronchopneumonia; ulcer of the esophagus and stomach

1204S

Rh

M

1 week

157

457.5

Congestion of the lung, spleen, and kidney; edema of the lung

826K

Gr

F

2 days

168

299.7

Septic hepatitis

821J

Gr

F

Birth

170

307.7

Septic hepatitis

1214S‡

Gr

M

Birth

192

467.1

Myocardial degeneration; atelectasis of the lung; congestion of the liver, lung, spleen, and kidney; hypoplastic bone marrow; atrophy of the thyroid; cholelithiasis

1207S

Rh

M

Birth

214

721.0

Myocardial fibrosis; congestion of the liver and lung; renal tubular necrosis; kyphosis

828K‡

Gr

F

1 day

Group 2: monke

282 ys euthanized a

473.6 fter >207 mont

Chronic ileitis hs in the experiment

1213S

Cy

F

Birth

207

318.7

Fatty infiltration of the liver; colloid cyst of the thyroid; endometriosis; chronic ulcer of the rectum; hydronephrosis of the kidney

1215S‡

Cy

M

1 day

213

803.0

Myocardial fatty infiltration; fatty infiltration of the liver; atrophy of the testis

1205S‡

Hybrid

F

3 days

214

598.9

Fatty degeneration of the liver; myocardial fibrosis and fatty degeneration

1209S‡

Rh

F

1 day

214

633.1

Ductal hyperplasia of the pancreas

1211S‡

Cy

M

1 day

214

658.3

Myocardial fibrosis and fatty degeneration; fatty infiltration of the liver; hyalinization of the pancreatic islet cells; atrophy of the testis

1212S‡

Cy

F

1 day

214

461.2

Myocardial fatty degeneration; fatty infiltration of the liver; hyalinization of the pancreatic islet cells

829K‡

Gr

F

Birth

281

515.6

Leiomyoma of the uterus; diverticulosis of the colon

820J‡

Rh

F

Birth

282

1021.5

Congestion and fatty degeneration of the liver; ovarian cyst

823J‡

Rh

M

Birth

282

1136.2

Fatty degeneration of the liver; colloid cyst of the thyroid

824K‡

Rh

M

Birth

282

1054.3

Lymphoma of thyroid; cyst of the pituitary gland

825K‡

Gr

F

10 days

282

455.4

Papillary cystadenoma of the ovary; leiomyoma of the stomach

818J

Cy

M

1 day

283

970.1

Myocardial fibrosis; liver cyst

*Rh 4 rhesus (Macaca mulatta); Cy 4 cynomolgus (Macaca fascicularis); Gr 4 African green (Cercopithecus aethiops).

†M 4 male; F 4 female.

‡Bladder observed by scanning electron microscopy.

Table 2. Major autopsy findings in control monkeys

Animal No.

Species*

Sex†

Euthanized or died‡

Observation, mo

Major histologic findings

1234T§

Cy

F

E

206

Myocardial degeneration; hyalinization of the pancreatic islet cells

1188S§

Cy

M

E

217

Atrophy, testis

1156R§

Rh

F

E

224

 

947M

Rh

M

E

234

 

944M

Rh

M

E

237

Fatty infiltration of the liver; hemorrhage and edema of the lung; inguinal hernia

987M

Cy

F

E

240

Hypertrophy of the left kidney; absence of the right kidney; endometriosis; oil injury of the right eye

1017N

Cy

M

E

244

Fibrosis, papillary muscle, left ventricle

1041N§

Cy

M

E

248

Atrophy of the testis; fatty infiltration of the liver; hyalinization of the pancreatic islet cells; cystic dilation of the prostate glands

989M§

Rh

M

E

257

Nodular cortical hyperplasia of the left adrenal

6971

Rh

M

E

261

Diverticulitis; emphysema and interstitial fibrosis of the lung

899L

Cy

M

E

268

Chronic bronchitis

901L§

Cy

F

E

277

Proliferation, follicular epithelial cell of the thyroid

778J

Rh

M

D

284

 

780J

Cy

M

D

285

Myocardial fibrosis; hyalinization of the pancreatic islet cells

779J

Rh

F

E

299

Fatty infiltration, clear cell foci of the liver; chronic gastritis; cholecystitis; adenomyosis of the uterus

678H

Cy

F

E

301

Fatty infiltration of the liver; hyalinization of the pancreatic islet cells; endometriosis; splenomegaly; hydronephrosis of the right kidney

*Rh 4 rhesus (Macaca mulatta); Cy 4 cynomolgus (Macaca fascicularis); Gr 4 African green (Cercopithecus aethiops).

†M 4 male; F 4 female.

‡E 4 euthanized; D 4 died.

§Urinary bladder examined by scanning electron microscopy.

 

Table 3. Urinary chemistries from monkeys ø2 years before being euthanized*

 

Control

Cynomolgus

Saccharin treated

Control

Female

Saccharin treated

 

Rhesus

 

Control

Male

Saccharin treated

 

Female

Control

Saccharin treated

pH

7.9; 6.6

7.6; 6.5

6.5; 6.1

7.1; 6.4

6.9; 7.1

7.2; 6.7

7.5; 6.1

7.9; 5.1

Protein

0.03; 0.0

0.07; 0.10

0.17; 0.11

0.24; 0.10

0.18; 0.08

0.07; 0.13

0.06; 0.08

0.16; 0.01

Sodium, mEq/L

20; <10

<10; <10

10; 83

23; <10

17; <10

20; <10

<10; <10

<10; <10

Potassium, mEq/L

24; 2

91; 4

29; 88

12; 26

34; 8

56; 6

16; 6

17; 2

Calcium, mg/dL

5; 3

110; 6

1; 109

9; 17

14; 10

16; 4

5; 6

4; 2

Phosphorus, mg/dL

2; 1

1; 1

—; 1

2; 2

1; <1

1; 1

1; 1

2; 1

Magnesium, mg/dL

2; 1

26; 2

1; 22

4; 11

5; 5

9; 2

2; 3

2; 1

Chloride, mEq/L

<15; 15

17; <15

<15; 63

13; <15

<15; <15

35; <15

<15; <15

<15; <15

Urea, mg/dL

217; 21

873; 62

204; 1380

263; 490

334; 104

575; 77

146; 129

155; 33

Creatinine, mg/dL

21; 9

130; 13

29; 233

23; 37

37; 14

65; 16

17; 19

22; 10

Osmolality, mOsm/kg

194; 25

527; 84

—; 959

237; 305

255; 90

384; 81

156; 184

159; 45

*Values are listed for individual monkeys (value from one monkey; value from second monkey).

 

Conclusions:
The results from this long-term study clearly show that there is no adverse effect of sodium saccharin administered in the diet of three species of monkeys beginning at birth and continuing for nearly the entire lifetime of the animals. Therefore, the test item is deemed non-carcinogenic.
Executive summary:

A carcinogenicity study of the test item in monkeys was performed following the National Cancer Institute’s nonhuman primate carcinogenicity testing program guides. Twenty monkeys underwent long-term treatment with sodium saccharin from 24h after birth and until the animals died or were euthanized at the end of the study (24 years). For group 1, total doses of test item consumed by these monkeys averaged 403.0 g and ranged from 229.9 to 721.0 g; for group 2, the total dose consumed averaged 718.9 g and ranged from 455.4 to 1136.2 g. The results from this long-term study clearly show that there is no adverse effect of sodium saccharin administered in the diet of three species of monkeys beginning at birth and continuing for nearly the entire lifetime of the animals. Therefore, the test item is deemed non-carcinogenic.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed

Carcinogenicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no study available

Carcinogenicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

A carcinogenicity study of the test item in monkeys was performed following the National Cancer Institute’s nonhuman primate carcinogenicity testing program guides. Twenty monkeys underwent long-term treatment with sodium saccharin from 24h after birth and until the animals died or were euthanized at the end of the study (24 years). For group 1, total doses of test item consumed by these monkeys averaged 403.0 g and ranged from 229.9 to 721.0 g; for group 2, the total dose consumed averaged 718.9 g and ranged from 455.4 to 1136.2 g. The results from this long-term study clearly show that there is no adverse effect of sodium saccharin administered in the diet of three species of monkeys beginning at birth and continuing for nearly the entire lifetime of the animals. Therefore, the test item is deemed non-carcinogenic.

Justification for classification or non-classification

Based on the available information, the test item is not classified for carcinogenic properties.