Immunohistochemical analysis of tumour regression grade for rectal cancer after neoadjuvant chemoradiotherapy

AIM

Tumour regression grade (TRG) as defined by Rödel et al. has been used as an independent prognostic factor for rectal carcinoma after preoperative treatment by chemoradiotherapy (CRT). Determination of TRG 2 and 3, semiquantitatively defined as more or less than 50% tumour regression, respectively, does not appear to correlate with prognosis. The purpose of this study was to find an immunohistochemical pattern to permit improved stratification of intermediate responders defined by disease free (DFS) and overall survival (OS).

METHOD

Immunohistochemistry of EGFR (epidermal growth factor receptor), VEGF (vascular endothelial growth factor), CD133 antibody, p53 antibody and Ki67 antibody was evaluated using tissue microarrays (TMA) on post-treatment surgical specimens from 88 patients. CD133 expression was confirmed in the whole section when available.

RESULTS

At a median follow-up of 40 months, TRG was found to be an independent predictor of DFS (P = 0.05) and OS (P = 0.001) but no differences were found between TRG 2 and 3 in terms of DFS (P = 0.74) or OS (P = 0.41). The results of TMA showed an immunohistochemically poor prognostic profile for intermediate responders configured by negativity of CD133 expression. However, when examining CD133 expression in the whole section, there was an intermediate correlation with TMA and the prognostic significance was lost.

CONCLUSION

The results did not confirm the value of immunohistochemistry in predicting the prognosis of patients with rectal cancer following neoadjuvant chemoradiotherapy. This questions the accuracy of TMA in detecting CD133 expression in this setting.

Red krypton and blue-green argon laser diabetic panretinal photocoagulation

Eyes with three or four diabetic retinopathy risk factors received laser panretinal photocoagulation with random selection of either blue-green argon (42 eyes) or red krypton (40 eyes) laser to determine if one laser was superior to the other. After 6 months, visual acuity preservation or improvement was obtained in 33 (79%) argon- and 34 (84%) krypton-treated eyes. Peripheral IV-4e visual field constriction of 7% occurred with argon and 10% with krypton. Vitreous hemorrhaging after treatment occurred in 1 argon- and in 6 krypton-treated eyes. Complete disc neovascular regression was obtained in 27 (67%) of 40 argon- and 19 (56%) of 34 krypton-treated eyes, with partial regression occurring in 8 (20%) argon- and 8 (24%) krypton-treated eyes. The two treatments produced essentially equal results.

Comparison of low- and high-volume irrigation-aspiration systems for extracapsular cataract extraction

A low-volume irrigation-aspiration system with a 1-mm tip (0.3-mm aspiration port) has been developed for extracapsular cataract extraction. This autoclavable system uses approximately 36% less irrigating fluid during the irrigation and aspiration of cortical material when compared to currently available models. The time required for cortical aspiration is also shortened by 33%. After three years of clinical experience with the low-volume system at the Miami Veterans Administration Medical Center, where almost all extracapsular cataract surgery is now performed with the new system, there have been no adverse effects and subsequent capsulotomy has rarely been necessary.

Snailtracks of the corneal endothelium

An unusual pattern of corneal endothelial cell alterations has been observed at the slitlamp in eyes following intraocular surgery. Because of their appearance, we have called these changes "snailtracks". We have commonly seen these snailtracks following extracapsular cataract extraction. Similar changes have been noted in cadaver corneas stored in McCarey-Kaufman (M-K) medium. This study presents information which suggests that these changes represent corneal endothelial cell damage.

Malignant fibrous histiocytoma of the orbit

A recent review of orbital tumors at the Armed Forces Institute of Pathology has shown that fibrous histiocytoma is the most common primary mesenchymal tumor of the orbit in adults. This surprising statistic is explained by the fact that the histologic classification of mesenchymal neoplasms has been revised extensively during the last two decades to include previously distinct tumors of fibrous tissue under the common histopathologic diagnosis of fibrous histiocytoma. We present the computed tomographic findings of a primary malignant fibrous histiocytoma of the orbit, along with a review of the literature.