Noelle L. Davis

A multicenter review of the treatment of major truncal necrotizing infections with and without hyperbaric oxygen therapy

To examine the effectiveness of hyperbaric oxygen (HBO) therapy in the treatment of major truncal necrotizing infections, a retrospective (1980 to 1992) analysis of the medical records of 30 patients treated with HBO therapy and 24 patients treated without HBO therapy was undertaken. The two groups were similar; however, there was a selection bias towards more frequent clostridial infections in a younger population in the HBO group. There was no difference in length of hospital stay, intensive care unit (ICU) stay, or duration of antibiotic therapy between groups. The mortality rates were 9/30 (30%) in the HBO group versus 10/24 (42%) (nonsignificant difference) in the non-HBO group. The total number of operations was greater in the HBO-treated group. This study failed to show that the use of HBO in the treatment of major truncal necrotizing infections statistically reduced mortality or the number of débridements. We believe, however, that the apparent selection bias and the trend towards increased survival in the HBO-treated group (12%) justifies the continued use of and research with HBO therapy.

Surgical Versus Percutaneous Drainage of Intra-Abdominal Abscesses

The records of 83 patients with intra-abdominal abscesses treated between 1986 and 1990 were reviewed to determine if there were significant differences in the outcome of patients treated by surgical drainage (n = 41) or percutaneous drainage (n = 42). The two groups were matched for age, abscess location, and etiology. Parametric statistical evaluations included the Students t test as well as analysis of variance; nonparametric statistics used were chi-square and Wilcoxon rank sums. No significant difference was found in mortality (surgical 14% versus percutaneous 12%) or morbidity (surgical 26% versus percutaneous 29%). The duration of hospital stay was similar. Although there was no significant difference between the two groups in severity of illness as measured by APACHE II scores, these scores were significant in determining prognosis. APACHE II scores were significantly higher in non-survivors of both groups (23 versus 13) and also higher in those developing complications. A subgroup of patients with diverticular abscess was identified in whom percutaneous drainage enabled later resection with primary anastomosis without complication. This study indicates that percutaneous drainage of an intra-abdominal abscess is as efficacious as surgical drainage and that APACHE II scores are prognostic of both potential mortality and morbidity.

Squamous cell carcinoma of the tongue and lower oral cavity in patients under 40 years of age

Squamous cell carcinoma of the tongue and lower oral cavity is uncommon in patients under the age of 40 years. The site distribution and male to female ratio of patients differed markedly from those of the overall squamous cell carcinoma group. The tongue was by far the most common site, and the majority of patients were women. There were no apparent etiologic or biologic factors noted. Lymph node metastases occurred in 38 percent of our patients and were present in six of seven tumor-related deaths. Those patients who died usually had a poor response to initial treatment, and most were dead within less than 2 years after diagnosis. The overall cure rate in our study patients was much better than that for the overall group of patients, and this was especially so in patients with tongue cancer (80 percent absolute cure rate). Aggressive treatment and careful follow-up for recurrence or metastases are necessary.

Correlation of epidermal growth factor receptor and c-erbB2 oncogene product to known prognostic indicators of colorectal cancer

Both epidermal growth factor receptor (EGFr) and the oncogene product of c-erbB2 have been shown to be expressed by human malignancies, and in some cases to relate to clinical outcomes. This study investigates the correlation between the presence of these receptor proteins and known prognostic indicators of colorectal cancer. Indirect immunoperoxidase staining of 32 freshly frozen surgical specimens revealed an overall expression of EGFr and c-erbB2 of 43% and 38%, respectively. A significantly higher rate of EGFr expression was found in tumours of more advanced stage (Dukes C and D), poor differentiation and those exhibiting vascular and lymphatic invasion. The presence of the c-erbB2 protein did not correlate with any of these variables. Expression of these molecules appeared to be independent and positive staining for both receptors occurred in only 19% of cases. EGFr may play a future role as a prognostic tool in colorectal cancer.

Role of frozen section and clinical parameters in distinguishing benign from malignant follicular neoplasms of the thyroid

The determination of malignancy preoperatively or intraoperatively is difficult in patients with follicular neoplasms of the thyroid. This study reviews a series of 395 patients treated for follicular neoplasms at the Vancouver General Hospital and the British Columbia Cancer Agency between the years of 1955 and 1988, 198 of whom had frozen section at the time of surgery. Frozen section was 79% accurate in differentiating follicular adenomas from carcinomas, with a sensitivity of 52% and a specificity of 100%. The positive predictive value of a frozen section showing carcinoma was 100%, and the negative predictive value was 73%. An incorrect diagnosis of a benign lesion was made in 21% of patients in whom the final diagnosis by fixed section was carcinoma. These same statistics were calculated for patients aged greater than 50 years, tumor size greater than 3 cm, and patients with a history of previous neck irradiation, three clinical factors shown in a previous study to be strong prognostic indicators of malignancy. The results were compared with those found by frozen section. The implications of these results in terms of patient management are discussed.

Impact of cervical lymph node metastases from squamous cell cancer of the lip

The records of 123 patients with squamous cell cancer of the lip presenting to the Vancouver Clinic of the British Columbia Cancer Agency from 1984 and 1988 were reviewed, and 4 were excluded from the study for various reasons. Initial treatment was surgery in 40, radiotherapy in 61, and combined in 18 patients. The primary tumor was staged as TIS in 11, T1 in 57, T2 in 24, T3 in 15, T4 in 1, and undetermined in 11. Follow-up continued for a minimum of 2 years in all but five patients. Lymph node metastases developed in 19 patients, representing 18% of the 108 patients with invasive cancer. The size of the primary tumor correlated with the likelihood of metastases. The neck disease was controlled in only 8 of the 19 patients with metastases, whereas control of the primary tumor was achieved in all but 3 patients. It is concluded that the development of node metastases in patients with lip cancer is more frequent than commonly appreciated and is associated with a high mortality rate. Close follow-up is essential to allow early detection of neck involvement. Aggressive surgery is indicated when such involvement becomes evident.

An evaluation of prognostic scoring systems in patients with follicular thyroid cancer

BACKGROUND Prognostic scoring systems for thyroid cancer have not been investigated in patients with pure follicular cancer; thus, the purpose of this study was to compare the following prognostic indices: the European Organization for Research and Treatment of Cancer (EORTC) method; the Age, Grade, Extent, Size (AGES) score; and the Age, Metastasis, Extent, Size (ALIES) score. PATIENTS AND METHODS A retrospective study reviewing 122 patients actively treated between 1955 and 1990 was conducted. Scoring systems were calculated and survival analysis completed. AGES low-risk patients were analyzed with respect to known risk factors. RESULTS The AGES scoring system significantly defined low- and high-risk groups (P = 0.0041); the ratio of deaths between high-versus low-risk groups was 1.9:1. EORTC scores distinguished four risk groups (P = 0.002). The AMES scoring system did not significantly assign risk. In multivariate analysis of low-risk AGES patients, age, perithyroidal tissue involvement, and positive frozen section reached statistical significance. CONCLUSIONS The AGES and EORTC scoring systems best defined low- and high-risk groups of patients with pure follicular cancer, although the separation between groups was low.

Effects of positive resection margin and tumor distance from anus on rectal cancer treatment outcomes

PURPOSE Rectal cancer outcome depends on stage, technical aspects of surgical excision, and use of adjuvant chemoradiation. Here, we examine effects of positive resection margin and tumor distance from the anus in stage 2 and 3 cancers on 4-year disease-specific survival and recurrence. METHODS We reviewed all 495 rectal cancer patients registered in British Columbia in 1996. RESULTS There were 481 cases analyzed: 29 in situ, 134 stage 1, 107 stage 2, 100 stage 3, 83 stage 4, and 28 unknown stage. Survival was significantly affected by presence of positive resection margin in stage 2 and 3 cancers, P = 0.0001. Lower tumor distance from the anus for stage 2 and 3 cancers worsened survival, P = 0.0007, and overall recurrence, P =0.016, but not local recurrence, P = 0.11. Adjuvant postoperative combined radiation and chemotherapy in stage 2 and 3 cancers significantly improved survival, P = 0.070 and local recurrence, P = 0.018, but not overall recurrence, P = 0.19. CONCLUSIONS Presence of positive resection margin and tumor distance from the anus affect survival, local recurrence, and overall recurrence. Adjuvant postoperative combined radiation and chemotherapy improved our outcomes. Our local recurrence rates for rectal cancers are worse than currently reported standards of less than 10%. Improved surgical excision and use of adjuvant preoperative radiation and chemotherapy may improve outcome.

Photodynamic therapy of squamous cell carcinoma. An evaluation of a new photosensitizing agent, benzoporphyrin derivative and new photoimmunoconjugate.

Photodynamic therapy for cancer depends on the relatively selective distribution of photosensitizing agents to malignant as compared with normal tissues, rendering the malignant cells more susceptible to light-mediated damage. Photodynamic therapy has been used with only moderate success to date. The purpose of this study was to compare a new photosensitizing agent, benzoporphyrin derivative (BPD), to the standard agent presently in use, photofrin II, in a hamster cheek pouch model of squamous cell carcinoma. As well we have investigated the potential of using a tumour-specific monoclonal antibody-BPD conjugate to improve the tumour localizing properties of BPD. Treatment consisted of photodynamic therapy with either photofrin II, BPD, or a tumour-specific anti-epidermal growth factor receptor-BPD conjugate. Control groups of light alone, anti-EGFr, tumour non-specific MoAb, and tumour non-specific MoAb-BPD conjugate were included with the contralateral cheek pouch of each animal acting as a dark control. An assessment of differential delivery of BPD to tumour and to normal mucosa was undertaken using a spectrophotometric assay. Parametric statistical analysis included Students t-tests and linear regression while non-parametric analysis was undertaken using Fishers exact test. Animals receiving BPD alone demonstrated tumour-to-tissue levels of approximately 2:1 while animals receiving the tumour-specific anti-EGFr-BPD conjugate had significantly better tumour:tissue ratios of 26:1 (P < 0.005). Animals treated with photofrin II had a 1 month cancer-free survival of 27% while animals treated with BPD had an improved survival of 67% (P = 0.03). The group treated with the tumour-specific anti-EGFr-BPD conjugate at a twentieth the total dose of BPD had an 80% 1 month cancer-free survival which was not statistically different from the group treated with BPD alone. Benzoporphyrin appears to be a more effective photosensitizing agent than Photofrin II and its tumour selectivity can be improved using a tumour specific monoclonal antibody conjugate.

Outcomes of sentinel node biopsy for breast cancer in British Columbia, 1996 to 2001

BACKGROUND This study evaluated the outcomes of the first 5 years of sentinel node biopsy (SNB) in British Columbia (BC), Canada, 1996 to 2001. METHODS There were 547 SNB procedures for breast cancer performed by 29 surgeons at 12 hospitals in BC between October 1996 and July 2001. Identification, accuracy, and false-negative rates were determined and correlated to patient, tumor, and surgical factors with the chi-square test. RESULTS SNB mapping was performed using blue dye alone (15%), radiopharmaceutical alone (6%), or both (79%). A completion axillary dissection was performed in 93%. A median of 2 (range 1 to 16) sentinel nodes was biopsied. The overall identification rate was 88%, accuracy was 92%, and false-negative rate was 22%. All rates were improved in younger (age <50 years) compared with older women. A positive lymphoscintiscan and the mapping agent used were associated with higher identification rates but not accuracy or false negative rates. Increasing surgeon experience was not significantly associated with improvements in identification or false-negative rates. CONCLUSIONS The potential of SNB was not fully translated into surgical practice in BC by 2001.