F.E. van Leeuwen

Risk of endometrial cancer after tamoxifen treatment of breast cancer

Since large trials have been set up to assess whether tamoxifen decreases the risk of breast cancer in healthy women, it has become important to investigate the drugs potential adverse effects, including occurrence of endometrial cancer. We undertook a case-control study in the Netherlands to assess the effect of tamoxifen on the risk of endometrial cancer after breast cancer. Through the population-based Netherlands Cancer Registry and two older, hospital-based, registries, we identified 98 patients who had endometrial cancer diagnosed at least 3 months after a diagnosis of primary breast cancer. Detailed information about treatment was obtained for all these patients, and for 285 controls, who were matched to the cases for age, year of breast cancer diagnosis, and survival time with intact uterus. Tamoxifen had been used by 24% of patients with subsequent endometrial cancer and 20% of controls (relative risk 1.3 [95% CI 0.7-2.4]). Women who had used tamoxifen for more than 2 years had a 2.3 (0.9-5.9) times greater risk of endometrial cancer than never users. There was a significant trend of increasing risk of endometrial cancer with duration of tamoxifen use (p = 0.049), and also with cumulative dose (p = 0.046). The duration-response trends were similar with daily doses of 40 mg or 30 mg and less. These findings support the hypothesis that tamoxifen use increases the risk of endometrial cancer. This oestrogenic effect on the endometrium was not related to the dose intensity. Physicians should be aware of the higher risk of endometrial cancer in tamoxifen users.

Second cancer risk following Hodgkin's disease: a 20-year follow-up study.

PURPOSE To determine risk factors for the development of second primary cancers during long-term follow-up of patients with Hodgkins disease (HD). PATIENTS AND METHODS We assessed the risk of second cancers (SCs) in 1939 HD patients, who were admitted to the Netherlands Cancer Institute (NKI; Amsterdam) or the Dr Daniel den Hoed Cancer Center (DDHK; Rotterdam) between 1966 and 1986. For 97% of the cohort, we obtained a medical status up to at least January 1989. The median follow-up duration of the patients was 9.2 years; for 17% of the patients, follow-up was longer than 15 years. For more than 98% of all second tumors, the diagnosis was confirmed through a pathology report. RESULTS In all, 146 patients developed a SC, compared with 41.9 cases expected on the basis of incidence rates in the general population (relative risk [RR], 3.5; 95% confidence interval [CI], 2.9 to 4.1). The mean 20-year actuarial risk of all SCs was 20% (95% CI, 17% to 24%). Significantly increased RRs were observed for leukemia (RR, 34.7; 95% CI, 23.6 to 49.3), non-Hodgkins lymphoma (NHL) (RR, 20.6; 95% CI, 13.1 to 30.9), lung cancer (RR, 3.7; 95% CI, 2.5 to 5.3), all gastrointestinal cancers combined (RR, 2.0; 95% CI, 1.2 to 3.1), all urogenital cancers combined (RR, 2.4; 95% CI, 1.4 to 3.7), melanoma (RR, 4.9; 95% CI, 1.6 to 11.3), and soft tissue sarcoma (RR, 8.8; 95% CI, 1.8 to 25.8). As compared with the general population, the cohort experienced an excess of 63 cancer cases per 10,000 person-years. Cox-model analysis indicated the following as significant risk factors for developing leukemia: first-year treatment with chemotherapy (CT), follow-up treatment with CT, age at diagnosis of HD greater than 40 years, splenectomy, and advanced stage. Patients treated with CT in the 1980s had a substantially lower risk of leukemia than patients treated in the 1970s (10-year actuarial risks of 2.1% and 6.4%, respectively; P = .07). Significant risk factors for NHL were older age, male sex, and combined modality treatment as compared with either modality alone. Risk of lung cancer was strongly related to radiotherapy (RT), while an additional role of CT could not be demonstrated. After more than 15 years of follow-up, women treated with mantle-field irradiation before age 20 years had a greater than forty-fold increased risk of breast cancer (P < .001). CONCLUSION While the long-term consequences of HD treatment as administered in the 1960s and 1970s are still evolving, it is promising that patients who received the new treatment regimens introduced in the 1980s have a much lower leukemia risk than patients treated in earlier years. Beginning 10 years after initial RT, the follow-up program of women who received mantle-field irradiation before age 30 years should routinely include breast palpation and yearly mammography.

Cancer risks in BRCA2 families: estimates for sites other than breast and ovary

Background: In BRCA2 mutation carriers, increased risks have been reported for several cancer sites besides breast and ovary. As most of the families included in earlier reports were selected on the basis of multiple breast/ovarian cancer cases, it is possible that risk estimates may differ in mutation carriers with a less striking family history. Methods: In the Netherlands, 139 BRCA2 families with 66 different pathogenic mutations were included in a nationwide study. To avoid testing bias, we chose not to estimate risk in typed carriers, but rather in male and female family members with a 50% prior probability of being a carrier (n = 1811). The relative risk (RR) for each cancer site with the exception of breast and ovarian cancer was determined by comparing observed numbers with those expected, based on Dutch cancer incidence rates. Results: We observed an excess risk for four cancer sites: pancreas (RR 5.9; 95% confidence interval (CI) 3.2 to 10.0), prostate (2.5; 1.6 to 3.8), bone (14.4; 2.9 to 42.1) and pharynx (7.3; 2.0 to 18.6). A small increase was observed for cancer of the digestive tract (1.5; 1.1 to 1.9). Histological verification was available for 46% of the tumours. Nearly all increased risks reached statistical significance for men only. Cancer risks tended to be higher for people before the age of 65 years. Moreover, families with mutations outside the previously defined ovarian cancer cluster region tended to have a higher cancer risk. Conclusions: We found that BRCA2 carriers are at increased risk for cancers of the prostate and pancreas, and possibly bone and pharynx. Larger databases with extended follow up are needed to provide insight into mutation specific risks of selected carriers in BRCA2 families.

Second cancer risk following testicular cancer: a follow-up study of 1,909 patients.

PURPOSE Improved survival in testicular cancer has been accompanied by concern about long-term side effects of therapy. We assessed the evolution of second cancer (SC) risk over a prolonged follow-up period, which has been rarely studied in large patient series. PATIENTS AND METHODS We estimated the risk of SCs in 1,909 patients with testicular cancer diagnosed in the Netherlands from 1971 to 1985. Complete medical information was obtained up to at least January 1988 for 92% of patients. Median follow-up was 7.7 years. For 89% of second tumors the diagnosis was confirmed through review of histologic slides; for an additional 8%, the diagnosis was verified by pathology reports only. RESULTS Seventy-eight patients developed a SC 1 year or more after start of treatment, as compared with 47.6 expected on the basis of incidence rates in the general population (relative risk [RR], 1.6; 95% confidence interval [CI], 1.3 to 2.1). The mean 15-year actuarial risk of all SCs was 9.8% (95% CI, 7.5% to 12.8%). Significantly increased RRs were observed for all gastrointestinal cancers combined (RR, 2.6; 95% CI, 1.7 to 3.9), stomach cancer (RR, 3.7; 95% CI, 1.8 to 6.8), contralateral testicular cancer (CLTC) (RR, 35.7; 95% CI, 21.8 to 55.2), and leukemia (RR, 5.1; 95% CI, 1.4 to 13.0). Patients who had received irradiation to the paraaortic lymph nodes and who survived testicular cancer for more than 5 years were at particularly high risk of developing stomach cancer (RR, 6.9; 95% CI, 3.3 to 12.7). The median interval between the diagnosis of testicular cancer and stomach cancer was 12.4 years. Patients treated with chemotherapy (CT) did not experience an increase in SCs in general. Indeed, CT-treated patients, as compared with those who received radiotherapy (RT), or surgery alone, had significantly reduced risk of CLTC. This finding might be attributed to an eradicating effect of CT on carcinoma in situ or subclinical CLTC. The excess risk of leukemia was not found to be clearly related to CT. CONCLUSION Testicular cancer patients who receive RT experience elevated risk of gastrointestinal tumors. CT does not seem to increase SC risk and may even decrease the risk of a CLTC. Following testicular cancer, the 15-year actuarial risk of all SCs is only about half the risk experienced by patients with Hodgkins disease.

Leukemia risk following Hodgkin's disease: relation to cumulative dose of alkylating agents, treatment with teniposide combinations, number of episodes of chemotherapy, and bone marrow damage.

PURPOSE The development of leukemia is one of the most serious long-term complications of modern treatment for Hodgkins disease (HD). This study was undertaken to examine the relation between risk of leukemia and various treatment factors (including cumulative dose of cytostatic drugs and interaction with radiotherapy [RT]), while also assessing the effect of treatment-induced bone marrow damage. PATIENTS AND METHODS We conducted a case-control study in a cohort of 1,939 patients treated for HD between 1966 and 1986 in the Netherlands. Detailed information from the medical records was obtained for 44 cases of leukemia and 124 matched controls, in whom leukemia had not developed. RESULTS The cumulative dose of mechlorethamine was the most important factor in determining leukemia risk. As compared with patients who received RT alone, patients treated with six or fewer cycles of combinations including nitrogen mustard (mechlorethamine) and procarbazine had an eightfold increased risk of developing leukemia (P = .08), while patients who received more than six of such cycles had a greater than 40-fold excess risk (P < .001). Treatment with lomustine or a combination of teniposide and cyclophosphamide also significantly increased the risk of leukemia. Patients who had received chemotherapy (CT) during two or more time periods had a nearly 40-fold increased risk of leukemia as compared with patients treated only once. The extent of RT did not further increase leukemia risk among patients who also received CT. A significantly increased risk of leukemia was found among patients with low platelet counts, both in response to initial therapy and during follow-up. Patients who experienced 2 or more half-year periods with platelet counts less than 75 x 10(6)/mL had an approximately fivefold risk of developing leukemia, and a similar risk increase was found for patients who responded to initial treatment with a > or = 70% decrease of platelet counts (as compared with patients who had a < or = 50% decrease). CONCLUSION In addition to mechlorethamine, lomustine and teniposide combinations were also linked to an elevated risk of developing leukemia. Since the number of CT episodes was found to be a strong determinant of leukemia risk, it is important that new therapies for HD continue to yield high initial cure rates. Further studies are warranted to investigate whether patients at high risk for developing leukemia may be identified from the response of their platelets to initial therapy for HD.

Increased risk of lung cancer, non-Hodgkin's lymphoma, and leukemia following Hodgkin's disease.

The risk of second cancers (SCs) was assessed in 744 patients with Hodgkins disease (HD) admitted to The Netherlands Cancer Institute from 1966 to 1983. Sixty-nine SCs were observed one month or more after start of first treatment. These included 14 cases of lung cancer, nine cases of non-Hodgkins lymphoma (NHL), 16 cases of leukemia, and six cases of the myelodysplastic syndrome (MDS). The median interval between the diagnosis of HD and that of second lung cancer, NHL, and leukemia was 8.1, 13.3, and 5.7 years, respectively. The overall relative risks (RR) (observed/expected [O/E] ratios) of developing lung cancer, NHL, and leukemia were 4.9 (95% confidence limit [CL], 2.7 to 8.2), 31.0 (95% CL, 14.2 to 58.9) and 45.7 (95% CL, 26.1 to 74.2), respectively. At 15 years the cumulative risk of developing an SC amounted to 20.6% +/- 2.9%. The 15-year estimates of lung cancer, NHL, and leukemia were 6.2% +/- 1.9%, 5.9% +/- 2.1% and 6.3% +/- 1.7%, respectively. Increased lung cancer risk following HD has not frequently been clearly demonstrated before; that we were able to demonstrate such risk may be due to the completeness of follow-up over long periods that could be achieved in this study. Excess lung cancer risk was only noted in treatment regimens with radiotherapy (RT); also, all lung cancers arose in irradiation fields. Excess risk of leukemia was only found in treatment regimens involving chemotherapy (CT). For NHL, combined modality treatment was shown to be the most important risk factor. Risk of lung cancer and NHL increased with time since diagnosis. A time-dependent covariate analysis (Cox model) performed on leukemia and MDS showed an increasing risk with intensity of CT, age (greater than 40 years), and a splenectomy.

Optimum number of oocytes for a successful first IVF treatment cycle

Ovarian stimulation in IVF allows selection of embryos for transfer, but may have detrimental effects on oocyte and embryo quality and endometrial receptivity. This study investigated the optimal response to ovarian stimulation in terms of number of oocytes for achieving pregnancy in a first IVF cycle. Data from 7422 women who underwent their first IVF cycle for standard indications were analysed. All had been treated with exogenous gonadotrophins and gonadotrophin releasing hormone (GnRH) agonist co-treatment in a long down-regulation protocol between 1990 and 1995. Pregnancy rates in relation to the number of obtained oocytes were adjusted for age, fecundity, subfertility cause, gonadotrophin dosage, type of luteal support, and number of transferred embryos by multivariate analysis. Of the 7422 women who underwent oocyte retrieval, overall 85% had an embryo transfer and 24% conceived. The highest pregnancy rates per embryo transfer and per started cycle were observed when 13 oocytes were obtained (31 and 28%, respectively). This study supports the concept of an optimal range of oocytes obtained in response to ovarian stimulation for IVF, below and above which outcomes are compromised.

Risk of borderline and invasive ovarian tumours after ovarian stimulation for in vitro fertilization in a large Dutch cohort

BACKGROUND Long-term effects of ovarian stimulation for IVF on the risk of ovarian malignancies are unknown. METHODS We identified a nationwide historic cohort of 19 146 women who received IVF treatment in the Netherlands between 1983 and 1995, and a comparison group of 6006 subfertile women not treated with IVF. In 1997–1999, data on reproductive risk factors were obtained from 65% of women and data on subfertility (treatment) were obtained from the medical records. The incidence of ovarian malignancies (including borderline ovarian tumours) through 2007 was assessed through linkage with disease registries. The risk of ovarian malignancies in the IVF group was compared with risks in the general population and the subfertile comparison group. RESULTS After a median follow-up of 14.7 years, the risk of borderline ovarian tumours was increased in the IVF group compared with the general population [standardized incidence ratio (SIR) = 1.76; 95% confidence interval (CI) = 1.16–2.56]. The overall SIR for invasive ovarian cancer was not significantly elevated, but increased with longer follow-up after first IVF (P = 0.02); the SIR was 3.54 (95% CI = 1.62–6.72) after 15 years. The risks of borderline ovarian tumours and of all ovarian malignancies combined in the IVF group were significantly increased compared with risks in the subfertile comparison group (hazard ratios = 4.23; 95% CI = 1.25–14.33 and 2.14; 95% CI = 1.07–4.25, respectively, adjusted for age, parity and subfertility cause). CONCLUSIONS Ovarian stimulation for IVF may increase the risk of ovarian malignancies, especially borderline ovarian tumours. More large cohort studies are needed to confirm these findings and to examine the effect of IVF treatment characteristics.

Autotransplantation of cryopreserved ovarian tissue in cancer survivors and the risk of reintroducing malignancy: a systematic review

BACKGROUND The risk of recurrent oncological disease due to the reintroduction of cancer cells via autotransplantation of cryopreserved ovarian tissue is unknown. METHODS A systematic review of literature derived from MEDLINE, EMBASE and the Cochrane Library was conducted. Studies on follow-up after autotransplantation; detection of cancer cells in ovarian tissue from oncological patients by histology, polymerase chain reaction or xenotransplantation; and epidemiological data on ovarian metastases were included. RESULTS A total of 289 studies were included. Metastases were repeatedly detected in ovarian tissue obtained for cryopreservation purposes from patients with leukaemia, as well as in one patient with Ewing sarcoma. No metastases were detected in ovarian tissue from lymphoma and breast cancer patients who had their ovarian tissue cryopreserved. Clinical studies indicated that one should be concerned about autotransplantation safety in patients with colorectal, gastric and endometrial cancer. For patients with low-stage cervical carcinoma, clinical data were relatively reassuring, but studies focused on the detection of metastases were scarce. Oncological recurrence has been described in one survivor of cervical cancer and one survivor of breast cancer who had their ovarian tissue autotransplanted, although these recurrences may not be related to the transplantation. CONCLUSIONS It is advisable to refrain from ovarian tissue autotransplantation in survivors of leukaemia. With survivors of all other malignancies, current knowledge regarding the safety of autotransplantation should be discussed. The most reassuring data regarding autotransplantation safety were found for lymphoma patients.

Long-term cause-specific mortality among five-year survivors of childhood cancer

The purpose of our study was to assess long‐term cause‐specific mortality of 5‐year childhood cancer survivors.