Transition of Ki-67 index of uterine cervical tumors during radiation therapy. Immunohistochemical study

Longitudinal Neuropathological Consequences of Extracranial Radiation Therapy in Mice

Cancer-related cognitive impairment (CRCI) is a consequence of chemotherapy and extracranial radiation therapy (ECRT). Our prior work demonstrated gliosis in the brain following ECRT in SKH1 mice. The signals that induce gliosis were unclear. Right hindlimb skin from SKH1 mice was treated with 20 Gy or 30 Gy to induce subclinical or clinical dermatitis, respectively. Mice were euthanized at 6 h, 24 h, 5 days, 12 days, and 25 days post irradiation, and the brain, thoracic spinal cord, and skin were collected. The brains were harvested for spatial proteomics, immunohistochemistry, Nanostring nCounter® glial profiling, and neuroinflammation gene panels. The thoracic spinal cords were evaluated by immunohistochemistry. Radiation injury to the skin was evaluated by histology. The genes associated with neurotransmission, glial cell activation, innate immune signaling, cell signal transduction, and cancer were differentially expressed in the brains from mice treated with ECRT compared to the controls. Dose-dependent increases in neuroinflammatory-associated and neurodegenerative-disease-associated proteins were measured in the brains from ECRT-treated mice. Histologic changes in the ECRT-treated mice included acute dermatitis within the irradiated skin of the hindlimb and astrocyte activation within the thoracic spinal cord. Collectively, these findings highlight indirect neuronal transmission and glial cell activation in the pathogenesis of ECRT-related CRCI, providing possible signaling pathways for mitigation strategies.

Modeling of non-small cell lung cancer volume changes during CT-based image guided radiotherapy: patterns observed and clinical implications

Background. To characterize the lung tumor volume response during conventional and hypofractionated radiotherapy (RT) based on diagnostic quality CT images prior to each treatment fraction. Methods. Out of 26 consecutive patients who had received CT-on-rails IGRT to the lung from 2004 to 2008, 18 were selected because they had lung lesions that could be easily distinguished. The time course of the tumor volume for each patient was individually analyzed using a computer program. Results. The model fits of group L (conventional fractionation) patients were very close to experimental data, with a median Δ% (average percent difference between data and fit) of 5.1% (range 3.5-10.2%). The fits obtained in group S (hypofractionation) patients were generally good, with a median Δ% of 7.2% (range 3.7-23.9%) for the best fitting model. Four types of tumor responses were observed-Type A: "high" kill and "slow" dying rate; Type B: "high" kill and "fast" dying rate; Type C: "low" kill and "slow" dying rate; and Type D: "low" kill and "fast" dying rate. Conclusions. The models used in this study performed well in fitting the available dataset. The models provided useful insights into the possible underlying mechanisms responsible for the RT tumor volume response.

Biopsy specimens obtained 7 days after starting chemoradiotherapy (CRT) provide reliable predictors of response to CRT for rectal cancer

PURPOSE

Preoperative chemoradiation therapy (CRT) significantly decreases local recurrence in locally advanced rectal cancer. Various biomarkers in biopsy specimens obtained before CRT have been proposed as predictors of response. However, reliable biomarkers remain to be established.

METHODS AND MATERIALS

The study group comprised 101 consecutive patients with locally advanced rectal cancer who received preoperative CRT with oral uracil/tegafur (UFT) or S-1. We evaluated histologic findings on hematoxylin and eosin (H&E) staining and immunohistochemical expressions of Ki67, p53, p21, and apoptosis in biopsy specimens obtained before CRT and 7 days after starting CRT. These findings were contrasted with the histologic response and the degree of tumor shrinkage.

RESULTS

In biopsy specimens obtained before CRT, histologic marked regression according to the Japanese Classification of Colorectal Carcinoma (JCCC) criteria and the degree of tumor shrinkage on barium enema examination (BE) were significantly greater in patients with p21-positive tumors than in those with p21-negative tumors (P=.04 and P<.01, respectively). In biopsy specimens obtained 7 days after starting CRT, pathologic complete response, histologic marked regression according to both the tumor regression criteria and JCCC criteria, and T downstaging were significantly greater in patients with apoptosis-positive and p21-positive tumors than in those with apoptosis-negative (P<.01, P=.02, P=.01, and P<.01, respectively) or p21-negative tumors (P=.03, P<.01, P<.01, and P=.02, respectively). The degree of tumor shrinkage on both BE as well as MRI was significantly greater in patients with apoptosis-positive and with p21-positive tumors than in those with apoptosis-negative or p21-negative tumors, respectively. Histologic changes in H&E-stained biopsy specimens 7 days after starting CRT significantly correlated with pathologic complete response and marked regression on both JCCC and tumor regression criteria, as well as with tumor shrinkage on BE and MRI (P<.01, P<.01, P<.01, P<.01, and P=.03, respectively).

CONCLUSIONS

Immunohistochemical expressions of p21 and apoptosis together with histologic changes on H&E-stained biopsy specimens obtained 7 days after starting CRT are strong predictors of the response to CRT.

E2F-1 binding affinity for pRb is not the only determinant of the E2F-1 activity

E2F-1 is the major cellular target of pRB and is regulated by pRB during cell proliferation. Interaction between pRB and E2F-1 is dependent on the phosphorylation status of pRB. Despite the fact that E2F-1 and pRB have antagonistic activities when they are overexpressed, the role of the E2F-1-pRB interaction in cell growth largely remains unknown. Ideally, it would be better to study the properties of a pRB mutant that fails to bind to E2F, but retains all other activities. To date, no pRB mutation has been characterized in sufficient detail to show that it specifically eliminates E2F binding but leaves other interactions intact. An alternative approach to this issue is to ask whether mutations that change E2F proteins binding affinity to pRB are sufficient to change cell growth in aspect of cell cycle and tumor formation. Therefore, we used the E2F-1 mutants including E2F-1/S332-7A, E2F-1/S375A, E2F-1/S403A, E2F-1/Y411A and E2F-1/L132Q that have different binding affinities for pRB to better understand the roles of the E2F-1 phosphorylation and E2F-1-pRB interaction in the cell cycle, as well as in transformation and gene expression. Data presented in this study suggests that in vivo phosphorylation at amino acids 332-337, 375 and 403 is important for the E2F-1 and pRB interaction in vivo. However, although E2F-1 mutants 332-7, 375 and 403 showed similar binding affinity to pRB, they showed different characteristics in transformation efficiency, G₀ accumulation, and target gene experiments.

Current advancement in radiation therapy for uterine cervical cancer

Radiation therapy is one of the effective curative treatments for uterine cervical cancer. However poor clinical results for the advanced stages require further improvement of the treatment. Intensive studies on basic and clinical research have been made to improve local control, primarily important for long term survival in radiation therapy. Regarding current advancement in radiation therapy for uterine cervical cancer, the following three major subjects are pointed out; technological development to improve dose distribution by image guided radiation therapy technology, the concomitant anticancer chemotherapy with combination of radiation therapy, and radiation biological assessment of the radiation resistance of tumors. The biological factors overviewed in this article include hypoxia relating factors of HIF-1alpha, SOD, cell cycle parameters of pMI, proliferation factors of Ki67, EGFR, cerbB2, COX-2, cycle regulation proteins p53, p21, apoptosis regulation proteins Bcl2 and Bax and so on. Especially, the variety of these radiation biological factors is important for the selection of an effective treatment method for each patient to maximize the treatment benefit.

Comparison of the radiobiological effect of carbon ion beam therapy and conventional radiation therapy on cervical cancer

Little clinical evidence has been provided to show the minimization of radiation resistance of tumors using high linear energy transfer radiation. We therefore investigated the radiobiological and molecular pathological aspects of carbon beam therapy. A total of 27 patients with squamous cell carcinoma (SCC) of the cervix were treated using a carbon beam and 50 control patients with SCC of the cervix using a photon beam. The expression of Ki-67, p53, and p27 proteins before radiotherapy and 5 and 15 days after therapy initiation were investigated using immunohistochemistry. Similar changes were observed in Ki-67 labeling index (LI) and p53 LI during carbon and photon beam therapies. However, for carbon beam therapy, the mean p27 LI significantly decreased from 25.2% before treatment to 18.6% on the 5th day after treatment initiation, followed by a significant increase to 36.1% on the 15th day. In contrast, for photon beam therapy, the p27 LI consistently decreased from the initial 19.9% to 13.7% on the 15th day. Histological effects were observably stronger under carbon than photon beam therapy, though no statistically significant difference was observed (p = 0.07 on the 5th day and p = 0.10 on the 15th day). The changes in p27 LI under carbon beam therapy were significantly different from those under photon beam therapy, which suggests important molecular differences in the radio-biological response between therapies. Further investigation is required to elucidate the clinical relevance of these putative changes and optimize the relative biological effectiveness of carbon beam to X-ray.

Cell resensitization after delivery of a cycle-specific anticancer drug and effect of dose splitting: Learning from tumour cords

After a single dose of an anticancer agent, changes due to cell death are expected to occur in the distribution of cells between proliferating and quiescent compartment as well as in the oxygenation and nutritional state of surviving cells. These changes are transient because tumour regrowth tends to restore the pretreatment status. The reoxygenation due to the decrease of oxygen consumption is expected to induce cell recruitment from quiescence into proliferation, and consequently to increase the sensitivity of the cell population to a successive treatment by a cycle-specific drug. In previous papers we proposed a model of the response of tumour cords (cylindrical arrangements of tumour cells growing around a blood vessel of the tumour) to single-dose treatments. The model included the motion of cells and oxygen diffusion and consumption. On the basis of that model suitably extended to better account for the action of anticancer drugs, we study the time course of the oxygenation and of the redistribution of cells between the proliferating and quiescent compartments. By means of simulations of the response to a dose delivered as two spaced equal fractions, we investigate the dependence of tumour response on the spacing between the fractions and on the main parameters of the system. A time window may be found in which the delivery of two fractions is more effective than the delivery of the undivided dose.

Oxygenated and reoxygenated tumors show better local control in radiation therapy for cervical cancer

The presence of hypoxic cells is one of the major factors affecting resistance against radiation therapy. In the clinical setting, little information exists as to the relationship between intratumoral oxygen partial pressure (pO(2)) and outcome. This study involved 30 consecutive patients with cervical cancer, who were treated with a combination of external and high-dose rate intracavitary irradiation. The pO(2) was measured before radiation therapy and at 9 Gy, using a needle-type polarographic oxygen electrode. The mean intratumoral pO(2) before radiation therapy was 17.3 +/- 10.8 mm Hg. The 3-year local control rates of patients with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg before radiation therapy were 52% and 100%, respectively, representing a significant difference (P= 0.035). At 9 Gy, mean intratumoral pO(2) was 23.6 +/- 9.1 mm Hg, a significant increase compared to the value before radiation therapy (P= 0.006). The 3-year local control rates of tumors with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg at 9 Gy were 35% and 93%, respectively, representing a significant difference (P= 0.001). The significantly better local control for oxygenated tumors at 9 Gy as well as before radiation therapy indicated that the oxygen effect and reoxygenation by radiation played an important role in local control in radiation therapy for cervical cancer.

Micronucleus test and observation of nuclear alterations in erythrocytes of Nile tilapia exposed to waters affected by refinery effluent

Micronuclei and nuclear alterations tests were performed on erythrocytes of Oreochromis niloticus (Perciformes, Cichlidae) in order to evaluate the water quality from Paraíba do Sul river, in an area affected by effluents from an oil shale processing plant, located in the city of São José dos Campos, Brazil-SP. Water samples were collected on 2004 May and August (dry season) and on 2004 November and 2005 January (rain season), in three distinct sites, comprising 12 samples. It was possible to detect substances of clastogenic and/or aneugenic potential, as well as cytotoxic substances, chiefly at the point corresponding to the drainage of oil shale plant wastes along the river. The highest incidence of micronuclei and nuclear alterations was detected during May and August, whereas the results obtained in November and January were insignificant. This work shows that the effluent treatment provided by the oil shale plant was not fully efficient to minimize the effect of cytotoxic and mutagenic substances in the test organism surveyed.

Mitotic index and ki-67 nuclear antigen labeling index as predictors of chemotherapy response in uterine cervical carcinoma

OBJECTIVE

The aim of this study was to determine if the mitotic index (MI) and the Ki-67 nuclear antigen labeling index (Ki67LI) obtained from biopsy specimens could be used as predictors of chemotherapy response in uterine cervical carcinomas.

METHODS

Six patients with squamous cell carcinoma who received neoadjuvant chemotherapy before radical surgery were entered into the study. The MI and the Ki67LI were evaluated using hematoxylin and eosin (H&E)-stained and immunostained slides before and after chemotherapy. Tumor size was measured three-dimensionally by magnetic resonance imaging. We compared the values of MI and Ki67LI with changes in tumor size.

RESULTS

The cases were classified according to the percentage reduction in tumor mass: one case showed a marked response (98%), four showed a moderate response (53-78%), and one showed a slight response (approximately 0%). In the case with a marked response, the MI values before chemotherapy and 3 and 7 days after chemotherapy were 15, 2, and 0, respectively. The corresponding Ki67LI values were 51, 16, and 0, respectively. In the moderate response cases, the corresponding MI values before and 3 and 7 days after chemotherapy were 3.9-13.6, 0.8-1.6, and 1.6-4.0, respectively. The Ki67LI was 21.8-44.2 before chemotherapy, with two cases increasing and two decreasing at 7 days after chemotherapy. In the case showing a slight response, the MI values before chemotherapy and 3 and 7 days after chemotherapy were 0.5, 0.8, and 1.0, respectively. The Ki67LI was 4.0 before chemotherapy and increased slightly to 6.0 at 7 days after chemotherapy.

CONCLUSIONS

In six cases examined, high MI and Ki67LI values before chemotherapy and a marked decrease in MI shortly after chemotherapy appeared to be predictors of good neoadjuvant chemotherapy response in uterine cervical carcinomas.

Modified partial hyperfractionation in radiotherapy for bulky uterine cervical cancer: reduction of overall treatment time

PURPOSE

The purpose of this study was to assess the feasibility and toxicity of modified fractionation of external beam radiation with the intention of reducing the overall treatment time (OT) by 1 week in cervical cancer.

METHODS AND MATERIALS

Thirty-one patients (Group 1, n = 31) with bulky cervical cancer (>/= 4 cm with Stage II and III, >/= 5 cm with Stage IB2) were entered into the twice a day (b.i. d.) protocol (18 Gy/10 fx in 2 weeks followed by 18 Gy/12 fx, b.i.d. in 6 days, then midline block at 36 Gy with 45 Gy to the whole pelvis and 51-59 Gy to the parametrium). These patients underwent high-dose-rate brachytherapy with 4 Gy/fx x 7 to point A, biweekly. During the same period, patients with non-bulky tumors (Group 2, n = 31) received conventional treatment and similar brachytherapy.

RESULTS

The OT of Group 1 was 7 weeks or less in 61.3%, 7.1-8 weeks in 29%, and more than 8 weeks in 9.7% (19.4%, 51.6%, and 29% in Group 2, respectively, p = 0.003). Incidences of acute complications and treatment breaks were similar in both groups. Late complication (rectal bleeding) occurred only in Group 1 (13%, 4/31), but was self-limited. Locoregional failures occurred within 2 years after completion of radiation therapy in both groups (16% and 13% in Group 1 and 2, respectively, with minimum and median follow-ups of 2 years and 34 months).

CONCLUSION

Partial hyperfractionation on the third week of radiation permitted patients to finish their treatment with shorter OT without excessive acute complications and with acceptable grade 2 late rectal bleeding complications. This treatment scheme may be an effective method for the improvement of local control of bulky cervical cancer.

Immunohistochemical prediction of radiation response and local control in radiation therapy for cervical cancer

Prognosis of 64 cervical cancer patients treated with radiation therapy was analyzed by tumor expressions of c-erbB-2 oncoprotein (CerbB-OPE) and p53 protein (p53-PE), Ki-67 growth fraction (Ki-GF), and the mitotic index of proliferating cell population (pMI). Positivity of CerbB-OPE and p53-PE was 42.4% and 84.6%, respectively. Mean Ki-GF and pMI were 33.0% and 2.7%, respectively. Mean Ki-GF for CerbB-OPE was 38.3%, significantly higher than the 26.2% for the negative patients (p < 0.01). The mean pMI for CerbB-OPE was 2.00%, significantly lower than the 3.70% of the negative patients (p < 0.05). The 5-year survival rate of CerbB-OPE-positive patients was 44.4%, significantly lower than the 74.8% of negative patients (p < 0.01). The survival rates of Ki-GF < 33% was 44.7%, significantly lower than the 87.5% of Ki-GF > or = 33% (p < 0.01). The survival rates of pMI > or = 3.5% was 0%, significantly lower than the 81.8% of pMI < 3.5% (p < 0.001). The survival rates of p53-PE-positive and negative patients were 52.8% and 85.0%, respectively (p > 0.1). The poor prognosis of the cervical cancer with CerbB-OPE, lower Ki-GF, and higher pMI were due to local recurrence following radiation therapy. Multiple regression analysis indicated that pMI was the strongest prognostic factor and was followed by CerbB-OPE, tumor volume, and Ki-GF. In conclusion, the c-erbB-2 oncoprotein expression, Ki-67 growth fraction, and the mitotic index of proliferating cell population were considered to be effective prognostic factors in radiation therapy for cervical cancer.

Relative changes of MIB1 and PC10 labeling indexes in cell kinetics during radiotherapy for cervical squamous cell carcinoma

To assess the changes in cell kinetics during radiotherapy (RT) in terms of the MIB1 and PC10 labeling indexes of cancer cells, a total of 230 biopsy specimens taken from 76 consecutive patients with cervical squamous cell carcinoma treated with RT was investigated. The MIB1 and PC10 indexes represent the growth fraction and proliferative activity, respectively. The MIB1 index ranged from 11 to 67% (mean value: 38%) before RT, from 21 to 86% (50%) at 5.4 Gy, from 15 to 85% (53%) at 9 Gy, and from 0 to 69% (26%) at 27 Gy. The PC10 index ranged from 4 to 46% (23%) before RT, from 5 to 62%, (26%) at 5.4 Gy, from 6 to 63% (23%) at 9 Gy, and from 0 to 35% (11%) at 27 Gy. The correlational relationships between the increment of both indexes during RT (delta index) and the index before RT were analyzed on an individual basis. The delta index was calculated by the index at various doses during RT minus the index before RT. Negative linear relationships were observed between the delta MIB1 index at 9 Gy or delta MIB1 index at 27 Gy and the MIB1 before RT, and also between the delta PC10 index at 9 Gy or delta PC10 index at 27 Gy and the PC10 index before RT. The linear regression coefficient values showed more than 0.5 (0.511 to 0.682) with statistical significance. According to these results, it was suggested that the cervical cancers of lower proliferative activity showed greater increases in growth fraction and proliferative activity by irradiation than those of higher proliferative tumors. These findings suggest that reversal patterns of changes in cell kinetics including growth fraction and proliferative activity took place in the early period of RT for cervical squamous cell carcinomas. The study of changes in cell cycle kinetics in human tumors during RT may have potential impact on the further development of RT.

The impact of tumour angiogenesis, p53 overexpression and proliferative activity (MIB-1) on survival in squamous cervical carcinoma

Tumour angiogenesis (antifactor VIII-related antigen antibody), p53 overexpression (DO-1) and proliferative activity (MIB-1) were immunohistochemically analysed for the prediction of long-term survival in 113 patients with squamous cervical carcinoma. The median follow-up time was 82 months (range 72-99). In early stages (IB-IIA), neovascularisation was significantly related to tumour size. Significantly more patients in stage IIA had high tumour vascularity compared to stage IB (P < 0.01) but no significant difference was found between early and advanced stages (IIB-IVB) of cervical carcinoma. p53 overexpression was correlated to the stage of disease (P < 0.01). No relationship was found between tumour angiogenesis, p53 overexpression or MIB-1 and pelvic lymph node metastases, histological subtype or differentiation. Tumours with more than 50% p53 overexpression was significantly correlated with survival in the univariate analysis, but no independent predictive value was found. It is concluded that immunohistochemically detectable p53 overexpression as measured by DO-1 and proliferative activity as measured by MIB-1 seems of no clinical value for the prediction of long-term survival in squamous cervical carcinoma. The predictive value of tumour angiogenesis for survival outcome has still to be determined in squamous cervical carcinoma.

Ki-67 antigen staining as an adjunct to identifying cervical intraepithelial neoplasia

The purpose of the work was to determine the feasibility and predictive value of Ki-67 immunostaining of cervical cytology and the detection of cervical dysplasia. Air-dried cervical smears were stained with MIB-1 antibody to identify the Ki-67 antigen. Nuclear decoration in abnormal squamous nuclei determined immunoreactivity. One hundred twenty-four nonpregnant patients underwent colposcopy and directed biopsies for abnormal cytology. Sensitivity (0.89), specificity (0.65), positive predictive value (0.60), and negative predictive value (0.91) were found for Ki-67 immunostaining in detection of high-grade cervical intraepithelial neoplasia (CIN) in 124 patients and positive Ki-67 staining was a significant predictor of high-grade CIN in both univariate (odds ratio 15.5 (95% CI 5.5-43.8) and multivariable (odds ratio 21.5 (95% CI 5.0-92.0) analysis. In 101 patients with ASCUS and LGSIL, Ki-67 immunostaining demonstrated the following in detection of high-grade CIN: sensitivity (0.96), specificity (0.67), positive predictive value (0.49), and negative predictive value (0.98). Ki-67 immunostaining of cervical cytology is a predictor of significant cervical pathology with high sensitivity and negative predictive value. Ki-67 immunostaining of cervical cytology may represent a new and cost-effective triage tool for patients with minor abnormalities on cytology.

Analysis of the proliferative potential of residual tumor after radiosurgery for intraparenchymal brain metastases

A retrospective immunohistochemical study of radiosurgically treated brain metastases was performed to determine whether residual tumor has reduced proliferative potential. The monoclonal antibodies MIB-10 and PC-10 were used as markers for proliferation. The experimental group consisted of pathological specimens obtained from five patients in whom brain metastasis previously had been treated with radiosurgery. Pathological specimens obtained from 10 patients with brain metastases, matched in histology to diseases in the experimental group but untreated by radiosurgery, served as controls. A significant decrease in proliferative indices was observed in metastatic brain cancers after radiosurgery (p < 0.001). These results indicate that the persistent tumor that is present at the site of a metastasis previously treated with radiosurgery is less viable and may not in itself be a significant finding.

Analysis of response to radiation therapy of patients with cervical adenocarcinoma compared with squamous cell carcinoma. MIB-1 and PC10 labeling indices

BACKGROUND

The MIB-1 monoclonal antibody is a marker of cycling cells and the PC10 monoclonal antibody is a marker of proliferating cell nuclear antigen in paraffin sections. This study was conducted to elucidate the difference in response to radiotherapy (RT) between cervical adenocarcinomas and squamous cell carcinomas, focusing on cell proliferation.

METHODS

A total of 196 biopsy specimens taken from the cervical carcinomas of 14 consecutive patients with adenocarcinoma and 62 patients with squamous cell carcinoma before and after RT at doses of 9 and 27 Grays (Gy) were investigated for MIB-1 and PC10 immunoreactivities.

RESULTS

In adenocarcinomas, the mean MIB-1 labeling indices before and after RT at 9 and 27 Gy were 28%, 21%, and 26%, respectively, whereas the mean PC10 labeling indices were 15%, 13%, and 14%, respectively. In squamous cell carcinomas, the mean MIB-1 labeling indices before and after RT at 9 and 27 Gy were 38%, 53%, and 26%, respectively, and the mean PC10 labeling indices were 23%, 23%, and 11%, respectively.

CONCLUSIONS

Cervical adenocarcinomas have a lower cycling cell population and their indices show no change during RT. Squamous cell carcinomas have a higher cycling cell population and show a transient increase of the MIB-1 cycling cell population at 9 Gy of RT. These findings suggest a difference in response to RT between adenocarcinomas and squamous cell carcinomas.

Prognostic significance of the MIB-1 proliferation index for patients with squamous cell carcinoma of the esophagus

BACKGROUND

A number of studies have indicated that the ki-67 proliferation index is of important prognostic significance for a variety of neoplasias. It was the aim of this study to investigate whether any correlation exits between the MIB-1 proliferation index and various clinicopathologic parameters in squamous cell carcinomas of the esophagus from 72 patients (20 women: median age, 64 years; range, 45-79 years; and 52 men: median age, 61 years; range, 43-77 years).

METHODS

Proliferative activity was determined using an immunohistochemical method with monoclonal antibody MIB-1 (ABC method), for tumor samples obtained from individuals who underwent esophagectomy in the period from 1983 to 1991. The percentage proliferation index (PI) was calculated as the number of positive cells divided by the total number of cells examined. Thirty-nine patients (54%) died of recurrence of esophageal cancer, with a median survival span of 15 months (range, 1-58 months). Thirty-three patients (46%) were still alive at the time of this study; their median follow up was 57 months (range, 40-98 months).

RESULTS

Significant differences between proliferative index values were recorded for the following parameters: survival rate, P < 0.0001; presence of lymph node metastasis, P < 0.05; size of the primary esophageal lesion, P < 0.01; proliferation pattern of the tumor, P < 0.01; and age of the patients, P < 0.05. No correlation was found regarding histologic differentiation, clinical stage, location of the lesion, intraepithelial cancerous spread, lymphatic and blood vessel invasion, and sex of the patients.

CONCLUSION

The MIB-1 proliferation index may be a powerful prognostic marker for patients with squamous cell carcinomas of the esophagus.

Rectal cancer: the influence of tumor proliferation on response to preoperative irradiation

PURPOSE

Regression of rectal carcinoma after preoperative irradiation is variable, likely reflecting differences in the physical and biologic properties of these tumors. This study examines the association between the pathologic response of rectal cancer after irradiation and its pretreatment proliferative state as assayed by the activity of the proliferative dependent antigens (Ki-67, PCNA) and mitotic counts.

METHODS AND MATERIALS

One hundred and twenty-two patients with locally advanced rectal cancer received preoperative irradiation followed by surgery. Pretreatment tumor biopsies were scored for the extent of Ki-67 and PCNA immunostaining and the number of mitoses per 10 high-powered fields. Postirradiation surgical specimens were examined for extent of residual disease.

RESULTS

The tumors of 38 of 122 patients (31%) exhibited marked pathologic downstaging (no residual tumor or cancer confined to the rectal wall) after preoperative irradiation. Two features were associated with the likelihood of marked pathologic regression after preoperative irradiation: tumor proliferative activity and lesion size. When stratified by lesion size, marked tumor regression occurred most frequently in smaller tumors with high Ki-67, PCNA, and mitotic activity compared to larger tumors with lower Ki-67, PCNA, and mitotic activity. Intermediate downstaging rates were seen for small or large tumors with moderate Ki-67, PCNA, and mitotic activity.

CONCLUSION

Tumor Ki-67, PCNA, and mitotic activity predicts the likelihood of response to irradiation, which may aid in formulating treatment policies for patients with rectal cancer.

Can Ki67 immunostaining predict response to radiotherapy in oral squamous cell carcinoma?

AIMS

To determine whether immunohistochemical evaluation of the abatement of proliferating cells after a first course of radiotherapy could predict the final response to treatment in oral squamous cell carcinoma (SCC).

METHODS

Frozen sections from 31 cases of histologically confirmed oral SCC were stained with the monoclonal antibody Ki67 at diagnosis and after 10 Gy of radiotherapy. The percentage difference of Ki67 positive cells among the biopsy specimens taken at the beginning and after 10 Gy was correlated with the clinical response obtained at the end of the treatment and its significance determined.

RESULTS

The percentage of Ki67 positive cells at diagnosis had no significant correlation with the final therapeutic result of radiotherapy. By contrast, the 32% difference of proliferating cells after 10 Gy of radiotherapy significantly differentiated responders from non-responders (p < 0.05). Furthermore, the abatement of the growth fraction after 10 Gy of radiotherapy was significantly correlated with the complete response (p < 0.01).

CONCLUSIONS

These data show that the immunohistochemical evaluation of the abatement of Ki67 positive cells after 10 Gy of radiotherapy provides an independent variable of responsiveness to radiotherapy, allowing a reliable prediction of the final therapeutic result to be made.

Transient increases of growth fraction during fractionated radiation therapy for cervical carcinoma. Ki-67 and PC10 immunostaining

BACKGROUND

The Ki-67 and PC10 indexes are consistent with the growth and S-phase fractions, respectively.

METHODS

Eighty-three biopsy specimens from 18 patients with cervical squamous cell carcinoma were examined before and during fractionated radiation therapy (RT), using an immunohistochemical method.

RESULTS

The 18 patients were divided into two groups according to the Ki-67 index before RT; those with values of less than 42% (Group A; n = 11) and those with values of 42% or more (Group B; n = 7). The Ki-67 index in Group A increased approximately twofold at radiation doses of 5.4-9 Gy compared with values before RT. The Ki-67 index in Group B, which increased slightly at doses of 5.4-9 Gy, decreased by approximately one-fifth at a dose of 27 Gy, compared with the value before RT. The PC10 indexes in both groups showed little change to doses of 5.4-9 Gy. The mitotic indexes were less than 1% before RT and decreased to a minimum with doses of 18-27 Gy. There was no correlation between the Ki-67 and PC10 indexes before or during RT.

CONCLUSION

In cancer tissues with a low growth fraction before RT, radiation doses of 5.4-9 Gy produced increases in the numbers of cycling cancer cells in the G1 or G2 phases. This transient increase possibly was attributable to the combined effects of the recruitment phenomenon and G1 or G2 block.

Differential values of Ki-67 index and mitotic index of proliferating cell population. An assessment of cell cycle and prognosis in radiation therapy for cervical cancer

BACKGROUND

Little is known about correlations between the growth fraction determined immunohistochemically with Ki-67 antibody and radiation response or prognosis after radiation therapy.

METHODS

The prognostic value of the growth fraction determined by Ki-67 index and the mitotic index of proliferating cell population (pMI) were assessed in 45 cervical cancers treated with radiation therapy. The specimens from the cervix before radiation therapy were immunohistochemically stained with anti-Ki-67 antibody.

RESULTS

The mean Ki-67 index and pMI for all patients were 36.0% and 2.74%, respectively. The patients with a Ki-67 index of 33% or greater showed significantly better histologic response to radiation at 30 Gy than those with less than 33%. The mean Ki-67 index for patients with good prognosis was significantly higher than for patients with tumor recurrence or metastasis later. Further, the mean values of pMI for patients with good prognosis were significantly lower than for patients with recurrence or metastasis. The 3-year survival rate for higher Ki-67 index (> or = 33%) was significantly better than lower Ki-67 index (less than 33%) (90.9% versus 34.8%; P < 0.001). However, the 3-year survival rate for higher pMI (> or = 3.5%) was significantly poorer than lower pMI (less than 3.5%) (8.3% versus 81.8%; P < 0.001).

CONCLUSIONS

These results suggested that tumors with a high growth fraction showed a good prognosis with radiation therapy. In addition, the inverse prognostic correlation between the Ki-67 index and pMI suggested that both indices have independent values on radiation response and prognosis after radiation therapy.

Cell-cycle analysis detecting endogenous nuclear antigens: comparison with BrdU-in vivo labeling and an application to lung tumors

The versatility of non-radioactive cell-cycle analysis in detecting endogenous nuclear antigens of the proliferating cells was evaluated. Optimal conditions for immunostaining varied in fixation and pretreatment procedures among antigens, bromodeoxyuridine (BrdU), Ki-67 epitope, DNA polymerase alpha and PCNA. A significant correlation between BrdU labeling index (LI) was observed in each positive ratio (PR, positive/total neoplastic cells) for nuclear antigens in tumor-sections which had been labeled in vivo with BrdU. The best correlation was observed in Ki-67 PR (y = 1.26x + 2.5; y = Ki-67 PR; x = BrdU LI; r = 0.97). To determine its prognostic value, Ki-67 analysis was applied to the surgically resected lung tumors. Ki-67 PR were different according to the histologic types of the tumors: 47.8 +/- 3.4% in small cell carcinoma; 29.5 +/- 3.5% in squamous cell carcinoma; 28.3 +/- 4.7% in large cell carcinoma; 15.2 +/- 1.8% in adenocarcinoma and 0.1 +/- 0.1% in mature carcinoid tumor. When the mean value was used to divide each type to a higher or lower proliferative activity (15% Ki-67 PR for adenocarcinoma and 30% for squamous cell carcinoma), the group with the lower Ki-67 PR showed a significantly more favorable prognosis than that of a higher ratio. Ki-67 PR was not correlated with other pathologic factors such as size, lymph node metastasis or pleural involvement. Non-radioactive cell-cycle analysis was feasible and useful for detecting endogenous nuclear antigens even in the lung tumors, particularly when the analysis was coupled with histologic typing.

Prognostic significance of the PC10 index as a prospective assay for cervical cancer treated with radiation therapy alone

The monoclonal antibody PC10 recognizes proliferating cell nuclear antigen (PCNA) in conventionally fixed and processed histologic materials. Formaldehyde-fixed and paraffin-embedded specimens taken from 194 patients with Stage III squamous cell carcinoma of the cervix treated with radiation therapy alone were investigated for PC10 positivity using immunohistochemical methods. A few squamous epithelial cells in the basal layer and the deepest zone of the prickle cell layer were positive for PC10. Cancer cells also were positive for PC10, showing a diffuse or granular nuclear staining pattern. The multiple logistic regression model analysis and the Kaplan-Meier method indicate that a strong correlation exists between the PC10 index and prognosis (P less than 0.001). Thus, the PC10 index may be a predictive indicator for the prognosis of patients with squamous cell carcinoma of the cervix treated with radiation therapy alone.