A cost comparison of two strategies for treating stage IB2 cervical cancer.

Patients with stage IB2 cervical cancer at our institution are treated primarily with definitive chemoradiation, or chemoradiation followed by adjuvant hysterectomy. We sought to compare the cost differences associated with these two strategies. We identified all patients with stage IB2 cervical cancer who received their entire treatment regimen at our institution between 1995 and 2004. All patients received a combination of chemotherapy, external beam radiation, and one brachytherapy procedure, followed by either a second brachytherapy procedure or a simple hysterectomy. We retrieved cost data associated with hospitalization for the completion of respective treatment, including pharmacy, laboratory and pathology, radiation, and operating room services, as well as the costs of supplies and room and board. We identified 46 patients with stage IB2 cervical cancer, 23 who received a second brachytherapy procedure and 23 who underwent simple hysterectomy. Patients displayed similar demographics and similar disease characteristics including initial tumor diameter and histology. The cost of care for adjuvant hysterectomy group was greater ($8,316.70 vs 5,508.70, P < 0.0001). Specific differences included higher operating room costs ($1520 vs 414, P < 0.0001), pharmacy costs ($675 vs 342, P < 0.0001), and laboratory/pathology costs ($597 vs 89, P < 0.0001). We conclude that definitive chemoradiation appears to be associated with lower costs for management of stage IB2 cervical cancer when compared to simple adjuvant hysterectomy.

Chemoradiation with and without adjuvant extrafascial hysterectomy for IB2 cervical carcinoma.

The optimal treatment strategy for stage IB2 cervical carcinoma that maximizes survival while minimizing toxicity remains controversial. The purpose of this study was to compare survival and toxicity in stage IB2 cervical cancer patients treated with chemoradiation and adjuvant extrafascial hysterectomy (cRT + H) versus definitive chemoradiation (cRT). Data were abstracted from patients with IB2 cervical carcinoma primarily treated at a single institution from January 1994 to December 2004. All patients received chemotherapy concurrent with external beam radiation therapy. Patients were subsequently treated with either a single low-dose rate brachytherapy applicator followed by adjuvant extrafascial hysterectomy (n = 24) or a second brachytherapy application to complete full-dose definitive chemoradiation (n = 30). Analyses were conducted using Kaplan-Meier survival and Chi-square statistics. Groups did not differ demographically with the exception of smoking. Smokers were significantly (P = 0.04) more likely to have been treated with definitive chemoradiation. Median tumor size was similar between groups. There was no difference in overall or disease-free survival between patients who received cRT + H versus cRT (P = 0.82 and 0.75, respectively). All recurrences in the cRT arm were in smokers. There were two grade 3-4 toxicities in each group. No treatment-related deaths occurred. In this small retrospective cohort study, we observed no difference in survival between patients treated with cRT + H versus cRT. These data complement published results of Gynecologic Oncology Group studies in patients with IB2 cervical cancer. Definitive comparison between the two treatment strategies would require a randomized prospective trial with stratification based on smoking.

Identification of growth hormone receptor (GHR) tyrosine residues required for GHR phosphorylation and JAK2 and STAT5 activation.

To determine whether GH receptor (GHR) cytoplasmic tyrosine residue(s) and tyrosine phosphorylation are required for signal transduction, we have substituted the eight porcine (p) GHR cytoplasmic tyrosines with phenylalanine individually or in a stepwise manner from the C terminus. Conversely, the eight tyrosines were individually regenerated in a non-tyrosine-containing pGHR analog. Mutated pGHR cDNAs were transfected into mouse L cells (MLCs) and cell lines were established. Each individual tyrosine-substituted pGHR analogs was able to activate STAT5 (signal transducer and activator of transcription 5; previously termed pp95) at levels comparable to those of wild type pGHR. Analyses of these pGHR analogs revealed that a single tyrosine residue at position 487, 534, 566, or 627 is sufficient for STAT5 phosphorylation. This result suggested that a redundancy in tyrosine residue requirement may be employed in GH-mediated signal transduction. Also, we found that the requirement of tyrosine residues for STAT5 phosphorylation directly correlated with their phosphorylation status. Combining both STAT5 and GHR tyrosine phosphorylation results, we have deduced that Y332, Y487, Y534, Y566, and Y627 are pGHR tyrosine phosphorylation sites. Additionally, Janus kinase 2 was activated by GH in all pGHR tyrosine-substituted analogs, including one containing no intracellular tyrosines, which agrees with a previous report that Janus kinase 2 activation is independent of GHR tyrosine phosphorylation.

Growth hormone promotes the association of transcription factor STAT5 with the growth hormone receptor.

Members of the cytokine/growth hormone (GH)/prolactin receptor superfamily transduce signals by association and activation of JAK tyrosine kinases. For GH receptor (GHR), both JAK2 and the GHR undergo tyrosine phosphorylation upon GH stimulation. Also, GH has recently been shown to activate the transcription factor STAT5 by tyrosine phosphorylation. In the present study, we demonstrate that GH induces rapid tyrosine phosphorylation of different isoforms of STAT5 in mouse L cells stably transfected with a cDNA encoding porcine GHR (pGHR). In this cell system, STAT5 directly interacts with the GHR in a GH-dependent manner. Additionally, GH-induced tyrosine phosphorylation of STAT5 and the interaction of STAT5 with GHR can be observed in mouse 3T3-F442A cells which express endogenous mouse GHR. Interestingly, when cDNAs encoding the two mouse STAT5 homologs (STAT5A and STAT5B) were individually transfected into mouse L cells expressing pGHR, only STAT5A demonstrated the ability to interact with the pGHR and subsequently underwent GH-dependent tyrosine phosphorylation. STAT5B did not. Therefore, the GH-dependent interaction of a particular STAT5 with tyrosine-phosphorylated GHR may play an important role in GH-mediated signal transduction.