Effect of continuous and pulsed therapeutic ultrasound in the appearance of local recurrence of mammary cancer in rats.

PURPOSE: Ultrasound (US) therapy is an electrothermotherapeutic modality that uses US energy to provoke physical and chemical alterations. US therapy has been widely used in physical therapy. However, in clinical practice, it is contraindicated in cancer patients due to the possibility of exacerbating tumor growth. METHODS: Sixty-eight female Sprague-Dawley rats bred in UNIFAE vivarium were studied. At 50 days of age, 7,12-dimetylbenz(a)anthracene (7,12-DMBA) was administered to 35 rats by gastric gavage to induce mammary cancer. After 90 days the mammary glands of the rats belonging to the group with mammary cancer induction and stimulated by US were removed. Animals received either continuous or pulsed US. US waves were generated at a frequency of 1 MHz during 10 days, with an intensity dose of 0.5 W in the continuous group, and 0.9 W (duty cycle: 20%) in the pulsed group. RESULTS: Among the rats treated with continuous US, 44.4% developed local recurrence, while among the rats treated with pulsed US, 22.2% had local tumor recurrence (p<0.05). No evidence of distant metastases was shown in any of the rats studied. CONCLUSION: The use of continuous and pulsed therapeutic US promoted the development of local recurrence of mammary cancer in female Sprague-Dawley rats in the postoperative period.

Vulvar carcinoma in young patients and its relationship with genital warts.

We report the occurrence of aggressive vulvar carcinoma associated with condyloma acuminata in three patients under 33 years old. Discussion of the role of the human papilloma virus (HPV) in the development of vulvar cancer is also presented. Three patients with condyloma associated with aggressive vulvar squamous cell carcinoma, in situ (1 case) and invasive (2 cases), documented by biopsy and/or vulvectomy are presented. In situ hybridization (ISH) was used to characterize the subtypes of HPV. One patient with erythematous systemic lupus developed in situ carcinoma after 5 years. The other two cases also developed aggressive multicentric, invasive squamous cell carcinoma after 10 years of diagnosis of condyloma. In all cases HPV cytological abnormalities were seen throughout the pathological examination. HPV 16 and 18 were present in cells of invasive squamous cell carcinoma in cases 2 and 3. HPV 6 and 11 were detected only in the condyloma area in case 2. HPV 30 was seen only in the condyloma area in case 3. This report emphasizes the need for biopsies of all unusually persistent or treatment-resistant condylomas, particularly in young and/or immunosuppressed patients.