Toshiyuki Maehama

Combination external beam radiotherapy and high-dose-rate intracavitary brachytherapy for uterine cervical cancer: Analysis of dose and fractionation schedule

PURPOSE To determine an appropriate dose and fractionation schedule for a combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT) for uterine cervical cancer. METHODS Eighty-eight patients with uterine cervical squamous cell carcinoma treated with EBRT and HDR-ICBT were analyzed. Twenty-five patients were classified as early disease (nonbulky Stage I/II, less than 4-cm diameter) and 63 patients as advanced disease (greater than 4 cm diameter or Stage IIIB) according to the American Brachytherapy Society definition. Tumor diameter was measured by MRI. Pelvic EBRT was delivered before applications of ICBT. HDR-ICBT was performed once a week, with a fraction point A dose of 6 Gy. Source loadings corresponded to the Manchester System for uterine cervical cancer. No planned optimization was done. A Henschke-type applicator was mostly used (86%). Median cumulative biologic effective dose (BED) at point A (EBRT + ICBT) was 64.8 Gy(10) (range: 48-76.8 Gy(10)) for early disease, and 76.8 Gy(10) (range: 38.4-86.4 Gy(10)) for advanced disease. Median cumulative BED at ICRU 38 reference points (EBRT + ICBT) was 97.7 Gy(3) (range: 59.1-134.4 Gy(3)) at the rectum, 97.8 Gy(3) (range: 54.6-130.4 Gy(3)) at the bladder, and 324 Gy(3) (range: 185.5-618 Gy(3)) at the vagina. Actuarial pelvic control rate and late complication rate were analyzed according to cumulative dose and calculated BED. RESULTS The 3-year actuarial pelvic control rate was 82% for all 88 patients: 96% for those with early disease, and 76% for advanced disease. For pelvic control, no significant dose-response relationship was observed by treatment schedules and cumulative BED at point A for both early and advanced disease. The 3-year actuarial late complication rates (Grade > or =1) were 12% for proctitis, 11% for cystitis, and 14% for enterocolitis. There were significant differences on the incidence of proctitis (p < 0.0001) and enterocolitis (p < 0.0001), but not for cystitis by the treatment schedules and cumulative point A BED. All 4 patients treated with 86.4 Gy(10) at point A suffered both proctitis and enterocolitis. Patients with cumulative BED at rectal point of > or =100 Gy(3) had significantly higher incidence of proctitis (31% vs. 4%, p = 0.013). CONCLUSIONS In view of the therapeutic ratio, cumulative BED 70-80 Gy(10) at point A is appropriate for uterine cervical cancer patients treated with a combination of EBRT and HDR-ICBT. Present results and data from other literatures suggested that cumulative BED at the rectal point should be kept below 100-120 Gy(3) to prevent late rectal complication.

A Large Case-Control Study of Cervical Cancer Risk Associated with Human Papillomavirus Infection in Japan, by Nucleotide Sequencing-Based Genotyping

Using nucleotide sequencing-based genotyping, we conducted a case-control study to examine cervical cancer risk associated with human papillomavirus (HPV) infection in a Japanese population. A consensus primer pair was used to amplify DNA from the L1 region of HPV by polymerase chain reaction (PCR). By PCR, 311 of 356 patients with cervical cancer and 333 of 3249 control individuals were positive for HPV. By the direct sequencing of PCR products, nucleotide sequences of 30 genotypes were obtained. A high incidence of type 52 and a low incidence of type 16 were characteristic of the control group. Odds ratios were estimated for 18 genotypes. Types 71, 90, and 91, previously uncharacterized, were classified as low-risk genotypes, which is consistent with predictions made on the basis of phylogeny. The present study is the first large case-control study of its kind to use nucleotide sequencing-based genotyping.

Detection of human papillomavirus DNA in primary and metastatic lesions of carcinoma of the cervix in women from Okinawa, Japan.

Of 351 patients with invasive cervical cancer treated at Ryukyu University Hospital, Okinawa, 293 who were tested for human papilloma virus (HPV) DNA of the primary cervical lesion before the initiation of treatment were considered for the study. The polymerase chain reaction (PCR) was performed using fresh specimens, immediately after sampling. In 250 of 293 patients (85.3%), HPV DNA was detected in cervical tumor by PCR using L1 consensus primer. The positive rate by histology was 89.9% in squamous cell carcinoma, 93.8% in adenosquamous carcinoma, and 51.4% in adenocarcinoma. The former two figures were significantly higher than the latter (p < 0.001 and p = 0.002). Concerning identification of HPV types, HPV 16 was most predominant in squamous cell carcinoma, whereas type 18 was relatively high in adenocarcinoma. However, the type distribution of HPV was different to some extent from those in other countries. During treatment, 489 nodal and other tissue samples were obtained from 113 of 250 HPV DNA–positive patients, and were submitted to an assay of HPV DNA. HPV DNA was amplified in all 55 metastatic samples and also in 12 of 434 nonmetastatic tissues (2.8%). HPV types specified in these samples were always identical with the HPV types determined in their primary tumors. In 154 samples from 29 of 43 HPV DNA–negative patients, HPV DNA was not detected, either in 14 metastatic samples or in 140 histologically benign samples. Cancer-free, but HPV DNA–positive nodal, liver, and pulmonary tissues could be interpreted to be already involved at the time of examination, by observing the clinical course of the disease over time.

Prevalence of HPV infection in cervical cytology‐normal women in Okinawa, Japan, as determined by a polymerase chain reaction

Epidemiological studies have shown that onset of sexual activity at early age and sexual promis- cuity are risk factors for the development of cer- vical cancer, possibly related to human papillo- . wx mavirus HPV infection 1 . In this context, studying the prevalence of HPV in a population with high incidence rate of cervical cancer can be informative for investigating the etiology of the disease. We analyzed the age-related prevalence of HPV in a large number of Okinawan women with cytologically normal cervices, using the po- . lymerase chain reaction PCR . In the Okinawa prefecture which is the southern-most part of Japan in the subtropical zone, the incidence rate of cervical cancer is reported to be the highest in