Jonathan Waxman

Palliation of Malignant Intestinal Obstruction Using Octreotide

Vomiting due to malignant intestinal obstruction is an unpleasant terminal event in many cancer patients, which responds poorly to conventional therapies. Somatostatin and its long-acting analogues reduce intestinal secretion. For this reason, octreotide was used in a phase I/II study of patients with intractable vomiting secondary to intestinal obstruction due to malignant disease. Vomiting was controlled or the volume of nasogastric aspirate was markedly reduced in 18 of 24 (75%) patients receiving a subcutaneous infusion of octreotide (median initial dose 300, range 100-600 micrograms/day) for a median of 9.4 (range 1-38) days. A further 2 patients had partial relief of their symptoms. Octreotide is an effective treatment of nausea and vomiting due to malignant bowel obstruction.

Carboplatin-based chemotherapy for bladder cancer

Urothelial cancer is common and the prognosis of patients with locally advanced tumors treated with conventional treatment is poor. In this trial we examined responses among 72 urothelial cancer patients referred for treatment with MVMJ (methotrexate/vinblastine/mitoxantrone/carboplatin) chemotherapy. Sixty-four evaluable patients, 37 with locally advanced and 27 with metastatic urothelial cancer, were treated. Twenty-nine (45%) of the 64 patients had a complete or partial response, 15 (23%) had stable disease, and 13 (20%) had disease progression. The median survival of the responding patients has not been reached (range, 114 to 1184+ days). Twelve patients (32%) with locally advanced disease had a complete response to treatment; their median survival has not been reached and ranges up to 1131+ days. Five patients (18%) with metastatic cancer had a complete response to treatment and their median survival was 497 days (range, 184 to 637+). There were seven deaths within the first treatment month.

Expression of the type 1 tyrosine kinase growth factor receptors EGF receptor, c-erbB2 and c-erbB3 in bladder cancer.

Expression of the c‐erbB3 protein was determined in transitional cell carcinoma of the bladder by immunohistochemistry. Strong membrane staining was observed in 10 per cent of cases (7/70) and cytoplasmic and membrane overexpression in 20 per cent (14/70). Overexpression of the epidermal growth factor (EGF) receptor (36 per cent, 25/70) and c‐erbB2 proteins (9 per cent 6/70) was determined in the same series of cases. c‐erbB3 overexpression was positively correlated with EGF receptor expression (P<0·025) but appeared to be inversely associated with c‐erbB2 overexpression.

The partial purification and characterization of GnRH-like activity from prostatic biopsy specimens and prostatic cancer cell lines

We have investigated the possibility of the secretion of gonadotrophin-releasing-hormone (GnRH)-like peptides by prostatic cancer cells in culture and their presence in cytosolic preparations from human prostatic biopsy specimens. A GnRH-specific radioimmunoassay showed GnRH-like activity in concentrated cytosolic preparations and conditioned media from DU 145, an androgen-insensitive human prostatic cell line and from LNCaP, an androgen-responsive prostatic cancer cell line. GnRH immunoreactivity in culture media correlated directly with cell numbers. HPLC demonstrated that this GnRH-like material co-migrated with synthetic GnRH. This homology between synthetic GnRH and partially purified prostatic GnRH was confirmed following V8 protease and trypsin digestion which resulted in similar alterations in HPLC characteristics. The mean content of GnRH-like activity/g specimen tissue was significantly more in malignant tissue (88.5 +/- 80.5 fmol) than in benign (29.6 +/- 22 fmol), though more specimens of benign tissue were positive (37/54) than malignant tissue (6/22). This observation, taken with an earlier finding of GnRH-specific receptors in a hormone-sensitive cell line and human cancer specimens provides supportive evidence for the autocrine hypothesis of cell regulation.

Combined choriocarcinoma and yolk sac tumor arising in Barrett's esophagus

A patient with primary adenocarcinoma with yolk sac and trophoblastic differentiation occurring in Barretts esophagus is reported. Yolk sac differentiation at this site has not been described previously. The diagnosis of germ cell differentiation initially was suggested by the finding of elevated serum tumor marker levels. The patient experienced disease remission after cytotoxic chemotherapy.

c-myc oncogene expression and clinical outcome in carcinoma of the cervix

The expression of the c-myc oncogene was studied in paraffin-embedded specimens of cervical biopsies using a monoclonal antibody which binds to the 62,000 Dalton protein encoded by the c-myc gene. A range of cervical cancers from intraepithelial neoplasia to advanced grade IV tumours were studied together with normal cervical biopsies; c-myc status was correlated to clinical progress. There was no correlation seen between the clinical stage of the disease at presentation and c-myc expression. The 15 patients with c-myc negative cervical cancers were shown to have better disease free (mean--95.4 mos) and total survival (mean 118.0--mos) compared to the 16 patients that were c-myc positive 28.4 and 48.4 mos respectively). The pattern of recurrence differed between the two groups with c-myc positive tumours more likely to develop extra pelvic metastatic disease. The c-myc status of cervical cancer offers a prognostic indicator that could be useful in guiding treatment decisions.

Sequential interleukin-2 and alpha interferon for renal cell carcinoma and melanoma

There is a theoretical basis for the synergy of interleukin-2 (IL-2) with other cytokines. We have investigated sequential treatment with IL-2 and alpha interferon. 1 of 22 patients with metastatic renal cell carcinoma had a partial response and one a minimal response to continuous infusion IL-2 but none of the 9 patients with melanoma responded. 16 of 17 patients with renal cell cancer, and 8 with melanoma, were then treated with alpha interferon. 2 patients with renal cell cancer responded to alpha interferon with sustained remissions of 30 and 40 months; both had responded to IL-2. The investigation of combination therapy with other cytokines is suggested, by these unusually long responses to alpha interferon.

Gonadotrophin-releasing hormone : physiological significance and relevance to cancer

Gonadotrophin releasing hormone (GnRH) is a decapeptide released by the hypothalamus. The binding of the peptide to pituitary receptors leads to the activation of second messenger systems. The physiological outcome of the exposure of pituitary cells to GnRH is the release of luteinising hormone (LH) and follicle-stimulating hormone (FSH). Continued exposure of these receptors to high concentrations of the peptide desensitises the receptor, thus inhibiting the release of gonadotrophins. This paradoxical effect has proved to be beneficial in the clinic where long-acting and enzyme-resistant analogues are used to inhibit the pituitary-gonadal axis, for example in the treatment of advanced prostatic cancer. In addition GnRH-analogues may affect tumour cells directly as observed in vitro. These direct effects have been described as inhibitory but recent data suggests that low concentrations of GnRH-analogues may stimulate short term growth of prostatic cancer cells in vitro. GnRH shares many other common characteristics with peptide growth factors, including common second messenger systems and receptor desensitisation on prolonged exposure to the ligand. It is possible that the direct inhibitory effects of GnRH-analogues are mediated through the desensitisation of tumour GnRH receptors, as suggested by recent observations. The nature and mechanism of the direct anti-tumour effect is important to understand and to promote the therapeutic efficacy of GnRH-analogues in the clinic.

Malignant mesenchymoma of the kidney

Malignant mesenchymoma is an uncommon tumour which shows at least two distinct types of mesenchymal differentiation in addition to an undifferentiated sarcomatous component. Most reported cases of malignant mesenchymoma have occurred in soft tissue of the retroperitoneum or thigh. Malignant mesenchymoma is rare in parenchymal organs and a review of the literature revealed only two previous case reports of malignant mesenchymoma in the kidney1.2.

Hormonal management of prostate cancer

In advanced disease, androgen deprivation remains the usual treatment. The completion of current trials is awaited to confirm whether total androgen blockade will prolong survival. To make further advances in treatment the fundamental biology of the prostate cell, benign or malignant, and its relationship to endocrine manipulation, must be understood. This may then lead to an understanding of clonal escape mechanisms in transformed cells and the clinical correlate of escape, relapse.