Controlling Taenia solium in Nepal using the PRECEDE-PROCEED model.

Taenia solium is a predominant food-borne parasitic zoonosis (FBPZ) in Nepal. Using the PRECEDE framework, as defined by Green and Kreuter, we can identify the factors behind the high incidence of this disease. Armed with this information, we can define the actions necessary to control T. solium. In accordance with the first step of PRECEDE, social assessment, we set the goal of decreasing the potential for T. solium transmission in Nepal by the year 2003. This goal has yet to be endorsed by policy makers. However, an epidemiological assessment based on hospital data alone showed that T. solium is an endemic problem in urban Nepal that must be addressed. Based on behavioral and environmental assessments (Steps 1 and 2 of PRECEDE-PROCEED), we defined the following action objectives to be achieved by 2003: 1) Train meat producers and sellers to detect contaminated pork and avoid selling it, 2) Improve pig husbandry to limit the animals' access to human feces, 3) Construct hygienic model slaughterhouses. These improvements could control the meat-producing environment, thus limiting the potential for cross-carcass contamination and other hygiene deficiencies associated with the spread of T. solium. An educational and ecological assessment shows all predisposing, reinforcing and enabling factors are present in Nepal, consistent with PRECEDE requirements. While T. solium is clearly defined as a health problem according to PRECEDE, there remain significant hurdles to controlling it. These hurdles lie in administration and policy, where standardized law-enforcement and meat inspection practices are needed. Finally, the government of Nepal must assign high priority to T. solium control, as it is a preventable, yet prevalent disease.

Ondansetron reduces chemotherapy induced nausea and vomiting refractory to standard antiemetics.

Ondansetron, a selective 5HT3 (serotonin) antagonist, was used in patients refractory to standard antiemetics. Seventy-five patients receiving chemotherapy without cisplatin were given ondansetron 4 mg IV and 4 mg orally immediately prior to chemotherapy, then 8 mg orally after six and 12 hours, followed by 8 mg orally eight hourly during days 2-5. Complete control of vomiting occurred in 52 patients (69%) on the first day and 45 patients (60%) on days 2-5. Sixty patients (80%) preferred ondansetron to their previous antiemetics. The efficacy of ondansetron was maintained over multiple chemotherapy cycles. Ondansetron was also given to 16 patients receiving cisplatin chemotherapy. They received 8 mg IV immediately prior to chemotherapy followed by an infusion of 1 mg/hr for 8 hr, with 8 mg orally at the end of the infusion and then 8 mg orally eight hourly during days 2-6. Some control of vomiting (less than = 5 vomits) was achieved in eight patients (50%) on the first day and in 14 patients (87%) on subsequent days. Eight patients (50%) preferred ondansetron to their previous antiemetics. Adverse events with ondansetron were frequent but mild, with constipation and headache being most common. Ondansetron is highly effective in patients refractory to standard antiemetics, especially after noncisplatin chemotherapy.

Reduction of carboplatin induced emesis by ondansetron.

Ondansetron is a selective 5-HT3 antagonist with significant antiemetic properties in patients receiving cytotoxic chemotherapy. Patients who had suffered severe vomiting on carboplatin alone (23 patients with ovarian carcinoma) or in combination (two patients with testicular cancer) despite intensive antiemetic regimens were treated with ondansetron, given as 8 mg immediately prior to carboplatin followed by 8 mg orally, 8 hourly for 5 days. Twenty-five patients received 58 courses of ondansetron. In the first 24 h after the first course of chemotherapy with ondansetron, 17 patients (68%) experienced no vomiting, five patients (20%) had almost complete control and the other three patients had partial control. During the subsequent 4 days slightly lesser control was achieved. Nausea was similarly controlled in most patients. Twenty-two patients stated a preference for ondansetron with future chemotherapy. Fourteen patients received additional chemotherapy with ondansetron and in only three patients did the efficacy of therapy lessen. Toxicity was mild and transient with headache and constipation predominant. No extrapyramidal reaction was seen. Sedation was absent. Ondansetron is highly effective in refractory vomiting associated with carboplatin chemotherapy. It may be particularly beneficial when an extrapyramidal reaction has occurred on previous antiemetics and when sedation is unacceptable.

Seasonal change in the concentration of progesterone receptor in breast cancer.

There are conflicting reports of seasonal changes in steroid hormone receptor levels in breast cancer tissue. Estrogen receptor and progesterone (PR) receptor levels from 1132 tumors were thus grouped according to month of initial tumor detection or month of tissue sampling/surgery. There was a significant circannual variation in the mean monthly PR receptor concentration in patients grouped according to month of tissue sampling/surgery with peak PR levels in April (late summer-early autumn) and nadir values in August and September (late winter-early spring). There was no significant cyclic variation in estrogen receptor values. A significant annual variation in tumor PR concentration was also seen when receptor levels from individual tumors were grouped according to month of initial tumor detection, with peak PR levels found in January and February. The time interval between tumor detection and biopsy/surgery was 3.3 +/- 5.3 months (mean +/- SD) which was close to the interval between the peak PR concentration expressed by month of tumor detection compared with month of tissue sampling for receptor assay. There was also a significant seasonal variation in the month of initial tumor detection, with peak detection occurring in December (summer). The close synchrony between month of maximum tumor detection and month of peak PR concentration suggests that seasonal changes in detection of breast cancer may in part relate to seasonal changes in hormone responsiveness within tumor tissue.

Does delay in diagnosis of breast cancer affect survival?

1675 breast cancer patients in the Auckland regional area have been divided into two major groups according to delay in diagnosis greater or less than six weeks. Overall there is no difference in survival although the variables tumour size, skin attachment, and nipple retraction are more common in the group with longer delay, and grade III tumours in those with short delay. Three important prognostic variables (the presence of tumour steroid receptors, positive axillary nodes, and distant metastases at diagnosis) are equally distributed and have a similar effect on survival within the two delay groups. However, in a subgroup of women with negative axillary nodes, short delay is associated with poorer survival, independent of tumour size. More tumours with grade III histology and a negative progesterone receptor status are found in this subgroup. Thus, short delay may constitute a new prognostic variable of some importance when in association with negative axillary nodes.

Season of initial discovery of tumour as an independent variable predicting survival in breast cancer.

The month of initial detection of tumour was recorded in 2,245 patients with breast cancer and correlated with survival over a follow-up period of 1.5-10 years. Women who initially detected their breast cancer in spring/summer had a significantly longer survival than those detecting their tumour at other times of the year. Overall, this relationship was independent of nodal status, tumour size and hormone receptor status. However, when patients were divided into groups the survival advantage was significantly associated with receptor status and age. Women aged greater than or equal to 50 years with ER-positive and PR-positive tumours who discovered their initial tumour in spring/summer had significantly better survival than those detecting their tumours at other times of the year. Survival was also longer in women aged less than 50 years with receptor-negative tumours who initially found their tumours in spring/summer compared with the rest of the year. This study suggests that the season of first detection of a breast cancer relates significantly to the later behaviour of the tumour, and may reflect seasonal changes in hormone dependent growth.

Season of tumour detection influences factors predicting survival of patients with breast cancer.

The rate of initial detection of breast tumours varies during the year in a seasonal fashion, more tumours being discovered in late spring/early summer than at other times of the year. This phenomenon is particularly pronounced in young women (less than 50 years) with progesterone receptor positive tumours. The present study investigates whether season of tumour detection influences the predictive capacity of several recognised prognostic and risk factors in patients with breast cancer. Axillary nodal status, tumour progesterone receptor status, and season of tumour detection significantly influenced survival in both older (greater than 50 yrs) and younger (less than 50 yrs) patients. Parity, lactational history, body mass index, tumour oestrogen receptor status, and patient age also influenced survival, but these effects were significant only in age groups less than 50 or greater than 50 yrs. Season of detection of tumour did not effect the prognostic significance of axillary nodal status. However, the effect of oestrogen receptor status on survival was more significant in patients who detected their tumours in the spring/summer compared with winter (odds ratio 0.52 and 0.73 respectively). Negative progesterone receptor status was associated with significant poorer survival only in patients with tumours found in the winter. There was a significant survival disadvantage for nulliparous compared with parous women with breast cancer who were greater than or equal to 50 years at diagnosis, and for women who had never lactated compared with those who had lactated, but this disadvantage was restricted to those who found their tumours in the summer. An increased body mass index (greater than or equal to 28) was associated with decreased survival, but this was significant only for those detecting tumours in winter. The increased incidence of detection of breast cancer in spring/summer may reflect cyclic influences on tumour growth. Such influences may be hormonal in nature and may underlie the effect of season of tumour detection on the prognostic influence of lactation, parity, body mass index, and oestrogen and progesterone receptor status in patients with breast cancer.

Influence of height, weight, and obesity on breast cancer incidence and recurrence in Auckland, New Zealand.

The relationship between obesity and breast cancer has been investigated in 1281 Auckland breast cancer patients. Using a definition of obesity as a Body Mass Index (BMI) of greater than or equal to 28 kg/m2, 179 (14%) breast cancer patients were classified as obese. The heights, weights, and BMI of 822 breast cancer patients aged 35-64 compared to 518 randomly selected Auckland women of similar age showed no significant difference. Within the breast cancer patients, there was no variation in nodal status or estrogen and progesterone receptor status between obese and non-obese women. However, tumours greater than 5 cm occurred significantly more often in obese patients. Time to recurrence was reduced in obese women with tumours less than or equal to 5 cm, no tumour in the axillary nodes, positive estrogen or progesterone receptor, and without metastases at the time of presentation of the disease. Although obesity has not been shown to influence breast cancer incidence, an effect on tumour recurrence is seen in patients with less advanced disease. This is similar to other reports which suggest that obesity is a weak but positive risk factor for recurrence.

Association between season of first detection of breast cancer and disease progression.

The season of recurrence of tumour was investigated by follow-up of 1324 patients with breast cancer and compared with the season of initial tumour detection. Unlike primary tumours, where an increased incidence of detection has previously been observed in late spring and early summer, there was no significant seasonal variation in the time of recurrence. However, women with oestrogen receptor positive or progesterone receptor negative primary tumours recurred significantly more frequently in the same season that their primary cancer was initially detected. Overall there was an increased frequency of recurrence one year from diagnosis. Women less than age 50 who initially found their tumour in winter or autumn had a significantly shorter disease-free interval before recurrence than those first detecting their tumour in summer or spring. This relationship was independent of nodal status and tumour size. Tumours initially detected in winter or autumn thus appeared to follow a more aggressive growth profile. This study indicates that the season of first detection of a breast cancer relates significantly to aspects of the future biologic behaviour of the tumour.