The risk of second primaries subsequent to irradiation for cervix cancer

Increased risk of second cancers at sites associated with HPV after a prior HPV-associated malignancy, a systematic review and meta-analysis

Background

High-risk human papilloma viruses (HPV) are a causative agent of anogenital and oropharyngeal cancers. Patients treated for a preinvasive or invasive HPV-associated cancer may be at increased risk of a second such malignancy.

Methods

We performed a systematic review and random effects meta-analysis to estimate the risk of HPV-associated cancer after prior diagnosis. Studies reporting second cancers at anogenital and oropharyngeal sites after prior diagnoses (preinvasive/invasive HPV-associated cancer) were identified. Studies reporting standardised incidence ratios (SIRs) were included in formal meta-analyses of second cancer risk. (PROSPERO ID: CRD42016046974).

Results

Searches returned 5599 titles, including 60 unique, eligible studies. Thirty-two (98 comparisons) presented SIRs for second cervical, anal, vulvo-vaginal, penile, and/or oropharyngeal cancers, included in the meta-analyses. All studies (and 95/98 comparisons) reported increased cancers in the population with previous HPV-associated cancer when compared to controls. Pooled SIRs for second primary cancers ranged from 1.75 (95% CI 0.66−4.67) for cervical cancer after primary anal cancer, to 13.69 (95% CI 8.56−21.89) for anal cancer after primary vulvo-vaginal cancer.

Conclusions

We have quantified the increased risk of second HPV-associated cancer following diagnosis and treatment for initial cancer or preinvasive disease. This has important implications for follow-up, screening, and future therapeutic trials.

Acute and long-term toxicity following radiotherapy alone or in combination with chemotherapy for locally advanced cervical cancer

Randomised studies in locally advanced cervical cancer patients showed that cisplatin should be given concurrently with radiotherapy, because of a better long-term survival compared to radiotherapy alone. This increases the relevance of treatment related toxicity. This review summarises the acute and long-term toxicity of radiotherapy given with or without chemotherapy for cervical cancer. Acute toxicity (all grades) of radiotherapy is reported in 61% of the patients in the rectosigmoid, in 27% as urological, in 27% as skin and in 20% as gynaecological toxicity. Moderate and severe morbidity consists of 5% to 7% gastrointestinal and 1% to 4% genitourinary toxicity. Adding chemotherapy to radiotherapy increases acute haematological toxicity to 5% to 37% of the patients and nausea and vomiting in 12% to 14%. Late effects of radiotherapy include gastrointestinal, urological, female reproductive tract, skeletal and vascular toxicity, secondary malignancies and quality of life issues. For at least 20 years after treatment, new side effects may develop. Gastrointestinal toxicity usually occurs in the first 2 years after treatment in about 10% of the patients. The incidence of moderate and severe urological toxicity can increase up to 10% and rises over time. Gynaecological toxicity usually occurs shortly after treatment while skeletal and vascular toxicity can occur years to decades later. Thus far, no increase in late toxicity has been observed after the addition of cisplatin to radiotherapy. Finally, methods to prevent or decrease late toxicity and therapeutical options are discussed. However, most randomised studies still have a limited follow-up period.

Conventional radiation therapy of cervical cancer

This review of the present literature about the conventional management of patients with definitive radiotherapy for invasive carcinoma of the cervix will focus on advances in the use of external-beam radiation therapy (EBRT) as well as in the administration of low-dose-rate brachytherapy for the delivery of radiotherapy. Important concepts discussed include: techniques and dose fractionation for EBRT; newer imaging modalities for administration of EBRT; construction of the midline shield for external irradiation of the pelvic nodes following brachytherapy; the role of elective para-aortic nodal external radiotherapy; and the adequate number of brachytherapy applications needed to impact on patient outcome. Considerable attention will be given to multi-institutional clinical data (e.g., the Patterns of Care Study and the Radiation Therapy Oncology Group) to illustrate advances in radiotherapy of patients with cervical carcinoma.

Postirradiation sarcoma of the gynecologic tract. A report of 13 cases and a discussion of the risk of radiation-induced gynecologic malignancies

With improvement in survival after cancer treatment, it is becoming increasingly important to examine treatment-related morbidity and mortality. Sarcomas can develop within the irradiated field after radiation therapy (RT) for gynecologic malignancies. We undertook a study to assess the outcome after treatment of postirradiation sarcoma (PIS) of the gynecologic tract. In reviewing our data and the literature, we compare the absolute risk of PIS and other radiation-associated second malignant neoplasms (SMNs) with the mortality risk of surgery and general anesthesia. Between 1955 and 1987, 114 patients with uterine sarcomas were seen at the University of California, Los Angeles (UCLA), Medical Center. Thirteen had a prior history of RT. Conditions for which these patients received RT included choriocarcinoma (one), menorraghia (four), cervical cancer (six), and ovarian cancer (two). RT doses were known in six cases and ranged from 4,000 to 8,000 cGy. Latency time from RT to the development of PIS ranged from 3 to 30 years, with a median of 17 years. Twelve patients were treated with surgery or additional RT. Two patients remain alive 5 months and 57 months, respectively, following salvage therapy. Five-year disease-specific survival for all patients is 17%. From our data and a review of the literature, we estimate that the absolute risk of PIS with long-term follow-up ranges from 0.03 to 0.8%. Postirradiation sarcoma of the gynecologic tract is a relatively rate event associated with a poor prognosis. Mortality risks of radiation-associated SMN are similar to mortality risks of surgery and general anesthesia. Given the large number of patients with gynecologic malignancies who can be cured or palliated with RT, concern regarding radiation sarcomagenesis should not be a major factor influencing treatment decisions.

Increased risk of second malignant neoplasms outside radiation fields in patients with cervical carcinoma

BACKGROUND

The relative risk of second primary cancers was evaluated in 125 women with International Federation of Gynecology and Obstetrics (FIGO) Stages I and II cervical carcinoma treated radically with radiation therapy between January 1980 and December 1990.

METHODS

Medical records of patients were reviewed to evaluate the incidence of second malignant neoplasms. Only tumors histologically proven were scored. The annual 5-year age-specific cancer incidence data per 100,000 white women in the years 1981-1985 were obtained from the National Cancer Institute's Surveillance, Epidemiology and End Results database. The relative risks were calculated as the ratio of observed-to-expected numbers of second cancers, using person-years at risk accumulated for each individual in the study.

RESULTS

During the follow-up time (through December 1992), 10 women whose median age was 65.5 years at the time cervical cancer was diagnosed were found to have 11 second primary cancers. Nine of these cancers were metachronous with regard to cervical cancer and included breast (4), lung (2), myeloma (1), non-Hodgkin's lymphoma (1) and vulva(1). The metachronous tumors were diagnosed at a median age of 74 years and at median follow-up time of 34 months. Two of the cancers were synchronous with cervical cancer and included bladder (1) and thyroid (1). All of the second tumors were located outside radiation fields. None of the patients with second tumors received chemotherapy during treatment for cervical carcinoma. The relative risk of developing a second cancer of any type was 2.31 (95% confidence interval [CI] = 1.15-4.13), whereas the relative risk of developing a metachronous breast cancer was 2.64 (95% CI = 0.72-6.75).

CONCLUSIONS

An increased risk of second primary cancers developing was observed among 125 patients with FIGO Stages I and II cervical carcinoma, which may suggest an abnormal genetic background and/or a common etiology for the initial and second tumors. The increased risk of breast cancer occurring as a second primary is in contrast with previously published studies reporting a decreased risk of breast cancer in survivors of cervical cancer.

Adjuvant radiotherapy and anastomosis in rectal cancer--disturbing evidence from animal studies

PURPOSE

Adjuvant radiotherapy is used increasingly in the management of rectal cancer. However, ionizing radiation is mutagenic, and, superimposed on a background of increased cellular proliferation as seen around anastomoses and in colorectal cancer patients, there is the potential for enhanced metachronous cancer risk.

METHOD

The influence of preoperative irradiation on both carcinogenesis and cellular proliferation at colonic anastomoses was explored in 180 adult male F344 rats. Orthovoltage x-rays were delivered to the distal descending colon by parallel opposed fields. Ninety rats received 16 Gy in one fraction; the remainder received 36 Gy in two fractions one week apart. In each irradiation group 18 rats either acted as controls or one week after radiotherapy underwent distal colotomy and repair.

RESULTS

We found the descending colon susceptible to radiation carcinogenesis; 26 colorectal tumors developed in the low-dose irradiation group and 47 in the high-dose group (P = 0.0008; Mann-Whitney U test, 16 vs. 36 Gy). Preferential tumor development was seen in the anastomotic region. In those animals that underwent surgery and irradiation, among the low-dose irradiation group only 3 of 72 had tumors within the descending colon compared with 21 of 72 at the anastomotic site (McNemar's test chi-squared = 40.9; P < 0.001), and in the high-dose irradiation group 5 of 72 had tumors within the descending colon compared with 36 of 72 at the anastomotic site (McNemar's test chi-squared = 22.0; P < 0.001). Anastomotic crypt cell production rates were increased for at least three months following exposure to irradiation (16 Gy: f = 15.1, P < 0.005; 32 Gy: f = 9.4, P < 0.005).

CONCLUSIONS

Radiation carcinogenesis is greatly enhanced at colonic anastomoses and may result from altered anastomotic proliferation. This has potentially disturbing implications in view of the increasing use of adjuvant radiotherapy for rectal carcinoma.

Mortality and cancer incidence following radiotherapy for seminoma of the testis

From the records of the Thames Cancer Registry, 859 patients were identified, who were treated with radiotherapy for seminoma of the testis between 1961 and 1985. Second cancer incidence and mortality and also causes of non-cancer deaths in the study population were examined. Fifty-one (6%) patients died of testicular cancer, 42 within 5 years of diagnosis. There were 42 second cancers (other than second testicular cancers), and 20 deaths from second cancer (expected, 22.1--non-significant). The only subtype of cancer with a notable excess was leukaemia (4 incident cases observed; 0.64 expected; relative risk 6.2, 95% C.I., 2.7-14.8, 95% C.I., 2.7-14.7). The overall death rate from causes other than testicular cancer was not elevated (82 observed, 82.06 expected). There was some suggestion of an increase in the risk of mortality with time; for 10 or more years after treatment the relative risk was 1.31 (95% C.I., 0.95-1.81). There was no evidence of excess non-cancer deaths (62 observed, 60 expected). We conclude that there is no definite evidence from this investigation of increased risk of mortality secondary to radiotherapy; however, the excess incidence of leukaemia may be treatment-related and the cohort will be followed further.

Second primary bladder cancer following pelvic irradiation for other malignancies

Between 1985 and 1990, five cases of radiation-induced bladder cancer were treated at our center. The first primary neoplasm was uterine cervical cancer in three patients, uterine endometrial cancer in one patient, and Hodgkin's disease in one patient. Additional treatment for the primary neoplasm included panhysterectomy for the patient with endometrial cancer and cyclophosphamide-based combination chemotherapy for the patient with Hodgkin's disease. The mean age at development of bladder cancer was 60.4 years, and the average time interval between irradiation and development of bladder cancer was 14.6 years. All the bladder cancers were invasive. The treatment modalities included anterior pelvic exenteration in one patient, partial cystectomy in one patient, reirradiation in two patients, including the use of intraoperative electron therapy in one patient, and TUR plus endoscopic Nd:YAG laser treatment in one patient. Four patients are alive without disease at a mean follow-up period of 15 months from the diagnosis of bladder cancer.

Second cancer after radiation therapy for cancer of the uterine cervix

Radiation-induced cancers after radiation therapy for cancer of the uterine cervix were investigated on 11,855 patients including 5725 patients treated with radiation therapy alone, 1969 postoperative radiation therapy and 4161 surgery alone. The observed-to-expected ratios of the second primary cancer was 0.933 for the patients with radiation therapy alone and 1.074 for the patients with postoperative radiation therapy, respectively. No significant increase was observed in the risk of second primary cancers when all sites were combined. However, assessing on site by site basis, significant excess was noted for the rectum cancer, leukemia, and bladder cancer for the radiation therapy group but not for the surgery group. A significant excess of lung cancer was observed in both radiation therapy and surgery groups, which was attributed to some other causative factors. Radiation-induced cancers were suggested to develop apparently in organs involved in the irradiated field.

Cancer of the vulva and vagina

Vulvar and vaginal cancer are rare malignancies and require aggressive treatment for survival. The prospect for cure in early stage disease is excellent. The major treatment modalities for these diseases, surgery and radiation, will affect structural alteration of the genitalia, requiring physical and psychological rehabilitation over an extended period of time. Quality of life is an important focus in cancer nursing. Efforts to control symptoms or adverse effects and to enhance the psychological adjustment are important aspects of patient care. Vulvar and vaginal cancer leave obvious residual effects, and disfigurement and dysfunction will be a part of these women's lives. Husbands and partners are also affected, and adjustments of both the patient and her partner are expected to continue for years. An active position assumed by the nurse will aid the patients' adaptive responses to these devastating diseases.

The value of pre-operative intracavitary radiotherapy in patients treated by radical hysterectomy and pelvic lymphadenectomy for invasive carcinoma of the cervix

Two hundred and twenty-four patients with invasive carcinoma of the cervix treated by radical surgery have been studied retrospectively to determine the impact of pre-operative intracavitary radiotherapy. Pre-operative radiotherapy made no difference to survival, the incidence of local recurrence, distant metastasis or complications.

Bladder cancer following low or high dose pelvic irradiation

Eleven women presenting to this department since 1971 with bladder cancer have had previous pelvic irradiation. The tumours were generally of high grade and advanced T-category. Prognosis was poor and only 32% survived for one year. The interval observed between low dose pelvic irradiation and subsequent bladder cancer was longer than after high dose pelvic irradiation (mean interval of 30 years compared with 16.5 years).

An excess of uterine sarcomas after pelvic irradiation

The Ohio State University Registry recorded 1208 uterine corpus malignancies between 1940 and 1983. Thirty cases occurred in women with a history of pelvic irradiation. Eight patients had previously been irradiated for pelvic malignancy, four of whom presented with advanced stage sarcomas and died of their disease within 14 months. This represents an increase over the expected sarcoma prevalence which is less than 5%. In contrast, the majority of women (20 of 22) previously irradiated for benign conditions were diagnosed with endometrial adenocarcinoma. In 18, the adenocarcinoma was diagnosed as Stage I, and the prognosis was only slightly less favorable than for nonirradiated women. No significant effect of age at the time of irradiation was apparent. This study of women with a history of pelvic irradiation who later developed uterine cancer demonstrates a tendency for patients previously irradiated for pelvic malignancy to present with advanced stage, extremely aggressive uterine tumors compared to those previously irradiated for benign conditions.

Transvaginal absorption of estrogens through irradiated mucosa

Serum concentrations of unconjugated estrone (E1) and 17 beta-estradiol (E2) have been measured in eight patients before and after 1.25 mg of conjugated estrogens administered intravaginally. The measurements were repeated using 2 mg of micronized estradiol administered intravaginally 1 week later to six of the women and 7 months later in one. All the patients had completed a full course of irradiation for pelvic malignancy at least 8 months prior to the study. Baseline, 1/2, 1-, 2-, 4-, 8-, and 24-hr samples were analyzed. After conjugated estrogens mean serum E2 increased 4.5-fold to peak at 163 pg/ml at 2 hr while serum E1 increased 3.2-fold to peak at 222 pg/ml at 2 hr. After micronized E2 mean serum E2 increased 89.3-fold to peak at 1250 pg/ml at 1 hr while E1 increased 3.1-fold to peak at 416 pg/ml at 2 hr. These data indicate that rapid absorption of E1 and E2 occurs through irradiated vaginal mucosa.