Abstract
A preponderance of carcinogenesis studies in rodents and epidemiologic studies in humans suggests a potential role of dietary fiber in the prevention of colorectal cancer. Recently, wheat bran fiber used as a dietary supplement has been shown to decrease the growth of rectal adenomatous polyps in patients with familial polyposis; however, few studies of high-risk human populations have been attempted to determine the effects of dietary fiber supplementation on markers of carcinogenesis in the colon or rectum. We have designed a one-arm study to evaluate the effects of dietary supplementation with wheat bran fiber [i.e., 13.5 g/day for 8 wk; after 1 mo, 2 g/day (compliance evaluation period)] on [3H]thymidine rectal mucosa cell labeling (i.e., percent of epithelial cells incorporating [3H]thymidine into DNA in intact rectal crypt cells over a 90-min exposure as well as in minced rectal biopsy tissue over a 24-hr exposure) in rectal biopsy specimens. The biopsy specimens were obtained at sigmoidoscopy in 17 compliant patients with a history of resected colon or rectal cancer. We categorized patients as having initially low or initially high [3H]thymidine-labeling indices (i.e., percent of mucosa cells that incorporate [3H]thymidine into DNA during 1.5- or 24-hour in vitro incubations) by using the median baseline labeling index as a cutoff between high and low values. On the basis of a chi-square test used to identify patients with a statistically significant (P < .001) change, six of the eight patients who initially had high 24-hour outgrowth labeling indices showed a significant decrease in the rectal mucosa biopsy specimens obtained after treatment. An overall 22% decrease was observed in rectal mucosa cell biopsy specimens obtained at study termination (P < .001). Of the eight patients with initially high total [3H]thymidine-labeling indices in crypt organ culture, four had a significant (P < .001) decrease from baseline values, one had a significant increase, and three showed no change following the fiber intervention. The wheat bran fiber dietary supplement of 13.5 g/day was well tolerated by this group of older (54-70 yr) patients. Although the [3H]-thymidine labeling index data suggest that the wheat bran fiber supplement can inhibit DNA synthesis and rectal mucosa cell proliferation in high-risk patients, the results of this small pilot study should not be overinterpreted vis à vis the potential role of wheat bran fiber as a chemopreventive agent for colorectal cancer. Study results should be confirmed in the setting of a randomized double-blinded clinical trial in colorectal cancer patients. Intermediate markers of carcinogenesis should be used as end points.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1280-1285 |
| Number of pages | 6 |
| Journal | Journal of the National Cancer Institute |
| Volume | 82 |
| Issue number | 15 |
| State | Published - Aug 1 1990 |
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ASJC Scopus subject areas
- Cancer Research
- Oncology
- Statistics, Probability and Uncertainty
- Applied Mathematics
- Physiology (medical)
- Radiology Nuclear Medicine and imaging
Cite this
Effects of dietary wheat bran fiber on rectal epithelial cell proliferation in patients with resection for colorectal cancers. / Alberts, D. S.; Einspahr, J.; Rees-McGee, S.; Ramanujam, P.; Buller, M. K.; Clark, L.; Ritenbaugh, C.; Atwood, J.; Pethigal, P.; Earnest, D.; Villar, H.; Phelps, J.; Lipkin, M.; Wargovich, M.; Meyskens, F. L.
In: Journal of the National Cancer Institute, Vol. 82, No. 15, 01.08.1990, p. 1280-1285.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effects of dietary wheat bran fiber on rectal epithelial cell proliferation in patients with resection for colorectal cancers
AU - Alberts, D. S.
AU - Einspahr, J.
AU - Rees-McGee, S.
AU - Ramanujam, P.
AU - Buller, M. K.
AU - Clark, L.
AU - Ritenbaugh, C.
AU - Atwood, J.
AU - Pethigal, P.
AU - Earnest, D.
AU - Villar, H.
AU - Phelps, J.
AU - Lipkin, M.
AU - Wargovich, M.
AU - Meyskens, F. L.
PY - 1990/8/1
Y1 - 1990/8/1
N2 - A preponderance of carcinogenesis studies in rodents and epidemiologic studies in humans suggests a potential role of dietary fiber in the prevention of colorectal cancer. Recently, wheat bran fiber used as a dietary supplement has been shown to decrease the growth of rectal adenomatous polyps in patients with familial polyposis; however, few studies of high-risk human populations have been attempted to determine the effects of dietary fiber supplementation on markers of carcinogenesis in the colon or rectum. We have designed a one-arm study to evaluate the effects of dietary supplementation with wheat bran fiber [i.e., 13.5 g/day for 8 wk; after 1 mo, 2 g/day (compliance evaluation period)] on [3H]thymidine rectal mucosa cell labeling (i.e., percent of epithelial cells incorporating [3H]thymidine into DNA in intact rectal crypt cells over a 90-min exposure as well as in minced rectal biopsy tissue over a 24-hr exposure) in rectal biopsy specimens. The biopsy specimens were obtained at sigmoidoscopy in 17 compliant patients with a history of resected colon or rectal cancer. We categorized patients as having initially low or initially high [3H]thymidine-labeling indices (i.e., percent of mucosa cells that incorporate [3H]thymidine into DNA during 1.5- or 24-hour in vitro incubations) by using the median baseline labeling index as a cutoff between high and low values. On the basis of a chi-square test used to identify patients with a statistically significant (P < .001) change, six of the eight patients who initially had high 24-hour outgrowth labeling indices showed a significant decrease in the rectal mucosa biopsy specimens obtained after treatment. An overall 22% decrease was observed in rectal mucosa cell biopsy specimens obtained at study termination (P < .001). Of the eight patients with initially high total [3H]thymidine-labeling indices in crypt organ culture, four had a significant (P < .001) decrease from baseline values, one had a significant increase, and three showed no change following the fiber intervention. The wheat bran fiber dietary supplement of 13.5 g/day was well tolerated by this group of older (54-70 yr) patients. Although the [3H]-thymidine labeling index data suggest that the wheat bran fiber supplement can inhibit DNA synthesis and rectal mucosa cell proliferation in high-risk patients, the results of this small pilot study should not be overinterpreted vis à vis the potential role of wheat bran fiber as a chemopreventive agent for colorectal cancer. Study results should be confirmed in the setting of a randomized double-blinded clinical trial in colorectal cancer patients. Intermediate markers of carcinogenesis should be used as end points.
AB - A preponderance of carcinogenesis studies in rodents and epidemiologic studies in humans suggests a potential role of dietary fiber in the prevention of colorectal cancer. Recently, wheat bran fiber used as a dietary supplement has been shown to decrease the growth of rectal adenomatous polyps in patients with familial polyposis; however, few studies of high-risk human populations have been attempted to determine the effects of dietary fiber supplementation on markers of carcinogenesis in the colon or rectum. We have designed a one-arm study to evaluate the effects of dietary supplementation with wheat bran fiber [i.e., 13.5 g/day for 8 wk; after 1 mo, 2 g/day (compliance evaluation period)] on [3H]thymidine rectal mucosa cell labeling (i.e., percent of epithelial cells incorporating [3H]thymidine into DNA in intact rectal crypt cells over a 90-min exposure as well as in minced rectal biopsy tissue over a 24-hr exposure) in rectal biopsy specimens. The biopsy specimens were obtained at sigmoidoscopy in 17 compliant patients with a history of resected colon or rectal cancer. We categorized patients as having initially low or initially high [3H]thymidine-labeling indices (i.e., percent of mucosa cells that incorporate [3H]thymidine into DNA during 1.5- or 24-hour in vitro incubations) by using the median baseline labeling index as a cutoff between high and low values. On the basis of a chi-square test used to identify patients with a statistically significant (P < .001) change, six of the eight patients who initially had high 24-hour outgrowth labeling indices showed a significant decrease in the rectal mucosa biopsy specimens obtained after treatment. An overall 22% decrease was observed in rectal mucosa cell biopsy specimens obtained at study termination (P < .001). Of the eight patients with initially high total [3H]thymidine-labeling indices in crypt organ culture, four had a significant (P < .001) decrease from baseline values, one had a significant increase, and three showed no change following the fiber intervention. The wheat bran fiber dietary supplement of 13.5 g/day was well tolerated by this group of older (54-70 yr) patients. Although the [3H]-thymidine labeling index data suggest that the wheat bran fiber supplement can inhibit DNA synthesis and rectal mucosa cell proliferation in high-risk patients, the results of this small pilot study should not be overinterpreted vis à vis the potential role of wheat bran fiber as a chemopreventive agent for colorectal cancer. Study results should be confirmed in the setting of a randomized double-blinded clinical trial in colorectal cancer patients. Intermediate markers of carcinogenesis should be used as end points.
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M3 - Article
C2 - 2165179
AN - SCOPUS:0025328638
VL - 82
SP - 1280
EP - 1285
JO - Journal of the National Cancer Institute
JF - Journal of the National Cancer Institute
SN - 0027-8874
IS - 15
ER -