Penetration Status Research Articles

Modified Extrafascial Radical Retropubic Prostatectomy Technique Decreases Frequency of Positive Surgical Margins in T2 Cancers

Objectives: In an effort to decrease the frequency of postoperative positive surgical margins (+SM), a modified extrafascial radical prostatectomy technique was developed and evaluated.Methods: 402 consecutive radical prostatectomy specimens removed for clinical stage T2 cancers from 1987 to 1994 were histologically examined prospectively for tumor volume, extraprostatic extension and +SM. Surgical technique modification was introduced in 1990. We compared the histologic status and biological outcome of the prostatectomy cases in 1987–1989 (n = 166) to those treated from 1990 to 1994 (n = 236).Results: The two series were comparable in (1) clinical stage and preoperative (PSA, (2) tumor volume, grade and location, and (3) capsular penetration, seminal vesicle and lymph node status. +SM fell from 32 to 25% overall, but for 146 (36%) prostates with a tumor volume <2 cm³, +SM fell from 21 to 6% which was statistically significant. Outcome measured by biological progression showed a decrease from 33% for +SM to 13% for –SM for cases with a tumor volume <2 cm³. For cancer volumes >2 cm³, the incidence of +SM did not vary significantly. We describe the anatomic details necessary for exposure of periprostatic fascias and extrafascial dissection at (1) the prostatourethral junction which ensures wide excision of the anterior and apical aspect of the prostate, (2) the posterior and apical area (development of the prerectal space), lateral and posterior areas at the base of the prostate which ensures wide excision of the rectoprostatic fascia (Denonvilliers’s fascia) and lateral prostatic fascia.Conclusions: Differences in surgical technique probably accounted for the significant decrease in +SM for those T2 cancers with volumes ≤2 cm³ which represents 36% of the T2 cancers in our series. Recent screening with PSA (T1c cancers) increases the incidence of these cancers ≤2cm³. This modified uni– or bilateral anatomic extrafascial prostatectomy with improved +SM and biological progression rates for T2 cases should be evaluated for T1c cases.

Numerical Dynamic Analysis of Moving GTA Weld Pool

A three dimensional model with a moving heat source is developed to describe heat transfer and fluid flow in transient weld pools. Full penetration and free top and bottom surfaces are incorporated in the model in order to simulate the welding process more practically. The influence of plate thickness and welding current on the dynamics of weld pools is analyzed using calculated data. It is shown that when the workpiece is nearly penetrated, the depth of weld pool increases quickly. Also, the elevation of the top surface decreases quickly once the full penetration status is established.

Endosonographic Evaluation of the Patient With Esophageal Cancer

The prognosis for patients with carcinoma of the esophagus remains poor despite the recent use of aggressive combination therapies and radical surgical resection. Attempts to improve the survival of patients with esophageal carcinoma have been confounded by a lack of effective therapeutic options in the later stages of the disease and an inability to accurately identify the early disease stages. Endoscopic ultrasound is a novel technique that affords close-proximity imaging of the esophageal wall and its adjacent structures. Endosonography is superior to CT scan for assessing depth of tumor penetration (T stage) and lymph node status (N stage). Recent advances in endoscopic ultrasonography include the ability to perform ultrasound-guided fine-needle aspiration of mediastinal masses and lymph nodes. Therefore, endosonography is ideally suited for staging esophageal cancers.

The Relationship of Local and Distant Failure from Endometrial Cancer: Defining a Clinical Paradigm

Purpose.Recently, statistical methods have been developed to rigorously assess the relationship between local and distant failures. Such methodology has successfully been applied to a variety of tumors including those arising in the prostate, breast, and cervix. To date, no published data are available to generate a hypothesis to characterize the relationship between local and distant failure for endometrial cancer. The present analysis was undertaken to determine the effect of locoregional control on subsequent metastatic dissemination among women with pathologically staged endometrial cancer treated by hysterectomy followed by adjuvant radiotherapy.Methods.The series consisted of 394 patients with FIGO stages I–III endometrial cancer who were surgically staged prior to irradiation [median external beam dose 45 Gy ± brachytherapy (median vaginal surface dose, 30 Gy)]. The duration of follow-up ranged from 2 to 151 months, with a median of 62 months. Multiple factors were evaluated to determine the associations with distant relapse including FIGO pathological stage, grade, histopathologic subtype (adeno vs papillary/papillary–serous/clear cell), depth of myometrial penetration, age, and local disease status. Time-dependent survival models were generated to assess the influence of local failure on distant metastases.Results.For the entire series, the 5-year actuarial rates of local and distant failures were 9 and 20%, respectively. Women who failed locally had nearly a fourfold risk of failing distantly compared to those who remained locally controlled (P= 0.02). Moreover, the earlier a local failure developed (e.g., within 1 year vs within 3 years), the more likely it was to be associated with distant metastases (P< 0.05). The univariate correlations of other factors with the 5-year rate of freedom from distant relapse also disclosed significant associations for grade, histology (adenoca vs papillary/papillary–serous/clear cell), and FIGO path stage. In multivariate analysis, only local control, low grade (grade 1 and 2), and early pathological stage were independently related to the likelihood of achieving freedom from distant relapse.Conclusions.Distant dissemination of endometrial cancer may develop secondary to local failure. Optimization of local control is therefore necessary if long-term cure is to be achieved. The limits of the current database cannot establish whether local failure is a cause of distant spread or a high-risk marker for metastases; however, ongoing national cooperative trials may resolve this controversy.

Real-Time Sensing of Sag Geometry During GTA Welding

Seam tracking and weld penetration control are two fundamental issues in automated welding. Although the seam tracking technique has matured, the latter still remains a unique unsolved problem. It was found that the full penetration status during GTA welding can be determined with sufficient accuracy using the sag depression. To achieve a new full penetration sensing technique, a structured-light 3D vision system is developed to extract the sag geometry behind the pool. The laser stripe, which is the intersection of the structured-light and weldment, is thinned and then used to acquire the sag geometry. To reduce possible control delay, a small distance is selected between the pool rear and laser stripe. An adaptive dynamic search for rapid thinning of the stripe and the maximum principle of slope difference for unbiased recognition of sag border were proposed to develop an effective real-time image processing algorithm for sag geometry acquisition. Experiments have shown that the proposed sensor and image algorithm can provide reliable feedback information of sag geometry for the full penetration control system.

Prediction of progression following radical prostatectomy. A multivariate analysis of 721 men with long-term follow-up.

We studied 721 men with clinically confined disease who underwent radical prostatectomy. No patient received preoperative or postoperative radiotherapy or hormone therapy until progression occurred. For those men without progression, the mean follow-up was 6.5 years with a median of 6 years (range 1 to 12 years). Because patients with lymph node metastases or seminal vesicle invasion had such a high risk of progression, enhanced prognostication was not needed in men with these findings. Thus we focused this analysis on the 617 men without lymph node metastases or seminal vesicle invasion. In the multivariate analysis, Gleason score (P < 0.0001), surgical margins (P = 0.004), and capsular penetration (P = 0.007) were all independent predictors of progression. Tumors with a Gleason score of 2 through 4 were almost invariably cured, with a 10-year progression-free risk of 96%. At the opposite end of the spectrum, the 10-year actuarial progression-free risk for men with a Gleason score of 8 through 9 was 35%. Men with Gleason score 2 through 4 or 8 through 9 tumors could not be stratified into different risks of progression based on the presence or extent of capsular penetration or margin status. For the men with Gleason score 5 through 7 tumors (88.2% of cases), predicting their risk of progression was enhanced by knowledge of their tumor's capsular penetration and margin status. Tumors with a Gleason score of 5 through 6 and 7 were each stratified into three groups with different risks of progression. Using the actuarial curves within this study, physicians will be able to more accurately determine a patient's risk of progression following radical prostatectomy based on a combination of the radical prostatectomy Gleason score, extent of capsular penetration, and status of surgical margins of resection.

Preoperative adjuvant radiation with chemotherapy for rectal cancer: Its impact on stage of disease and the role of endorectal ultrasound

Preoperative adjuvant radiation combined with chemotherapy is a recent development in the management of patients with rectal cancer invading perirectal tissue and regional lymph nodes. This study was performed to assess the impact of preoperative adjuvant therapy in patients judged by endorectal ultrasound to have extramural invasion of rectal cancer and/or regional lymph node involvement on tumor regression in bowel wall and lymph nodes. The predictive value of ultrasound in staging wall penetration and lymph node involvement after preoperative adjuvant therapy was also assessed. Patients (n = 43) were selected by ultrasound to have preoperative irradiation (4,500-5,040 cGy over 5-6 weeks). In 30 patients this was combined with 5-fluorouracil, 370 mg/m(2), for 5 days in the first and last weeks of irradiation. Pretreatment ultrasound was compared with pathologic findings in the resected specimen in all patients. Twenty-one were assessed by ultrasound after adjuvant therapy and findings compared with histology. Downstaging was seen in 23 (53%) patients with wall invasion and in 23 (72%) of 32 patients with lymph node involvement. Overall, downstaging was achieved in 30 (70%). Positive predictive values of ultrasound after irradiation were 72% and 56% for wall penetration and lymph node status, respectively. Negative predictive values of ultrasound after irradiation were 100% and 82%, respectively. In the majority of patients with rectal cancer invading perirectal tissues or lymph nodes, lesions may be downstaged by preoperative adjuvant therapy. Endorectal ultrasound after adjuvant therapy for rectal cancer is of a lesser predictive value chiefly because of overstaging.

37 The relationship of local and distant failure from endometrial cancer: Defining a clinical paradigm

Purpose. Recently, statistical methods have been developed to rigorously assess the relationship between local and distant failures. Such methodology has successfully been applied to a variety of tumors including those arising in the prostate, breast, and cervix. To date, no published data are available to generate a hypothesis to characterize the relationship between local and distant failure for endometrial cancer. The present analysis was undertaken to determine the effect of locoregional control on subsequent metastatic dissemination among women with pathologically staged endometrial cancer treated by hysterectomy followed by adjuvant radiotherapy. Methods. The series consisted of 394 patients with FIGO stages I-III endometrial cancer who were surgically staged prior to irradiation [median external beam dose 45 Gy ± brachytherapy (median vaginal surface dose, 30 Gy)]. The duration of follow-up ranged from 2 to 151 months, with a median of 62 months. Multiple factors were evaluated to determine the associations with distant relapse including FIGO pathological stage, grade, histopathologic subtype (adeno vs papillary/papillary-serous/clear cell), depth of myometrial penetration, age, and local disease status. Time-dependent survival models were generated to assess the influence of local failure on distant metastases. Results. For the entire series, the 5-year actuarial rates of local and distant failures were 9 and 20%, respectively. Women who failed locally had nearly a fourfold risk of failing distantly compared to those who remained locally controlled (P = 0.02). Moreover, the earlier a local failure developed (e.g., within 1 year vs within 3 years), the more likely it was to be associated with distant metastases (P < 0.05). The univariate correlations of other factors with the 5-year rate of freedom from distant relapse also disclosed significant associations for grade, histology (adenoca vs papillary/ papillary-serous/clear cell), and FIGO path stage. In multivariate analysis, only local control, low grade (grade 1 and 2), and early pathological stage were independently related to the likelihood of achieving freedom from distant relapse. Conclusions. Distant dissemination of endometrial cancer may develop secondary to local failure. Optimization of local control is therefore necessary if long-term cure is to be achieved. The limits of the current database cannot establish whether local failure is a cause of distant spread or a high-risk marker for metastases; however, ongoing national cooperative trials may resolve this controversy.

BARRIERS TO CANCER SCREENING

Many barriers to cancer screening have been summarized and discussed. Barriers have been documented in all patient populations, but some groups such as ethnic minorities and the elderly face unique barriers. The barriers to cancer screening, are multifactorial, but much of the responsibility for change must lie with health care providers and the health care delivery industry. This is not to free the patient of all responsibility, but some significant barriers are beyond their direct control. Take, for example, socioeconomic status, disease knowledge, and culturally related perceptions and myths about cancer detection and treatment. The health care industry must do a better job identifying and overcoming these barriers. The significant effects of provider counseling and advice must not be underestimated. Patients must first be advised, and then further actions must be taken if they reject the screening advice. Did they refuse adherence to recommendations because they do not view themselves as susceptible, because of overwhelming personal barriers, or because of a fatalistic attitude toward cancer detection and treatment? If that is the case, physicians and health care institutions must attempt to change perceptions, educate, and personalize the message so that patients accept their disease susceptibility [table: see text]. Multiple patient and provider risk factors have been identified that can be used to target patients particularly at high risk for inadequate cancer screening and providers at high risk for performing inadequate screening. Research has clearly demonstrated the effectiveness of interventions to improve tracking of patient and physician compliance with screening recommendations. Further research is needed to show the impact of managed-care penetration and payer status on screening efforts, and incentive schemes need to be tested that reward institutions and third-party payers who develop uniform standards and procedures for cancer screening. The greatest responsibility lies with medical and health care institutions and those who determine the priorities of these institutions. Patient and physician barriers to mass cancer screening can be addressed by institutional support. If the quality of care delivered by providers, group practices, managed-care organizations, and HMOs is assessed with priority given to the regularity and consistency with which basic screening procedures are performed, cancer screening will undoubtedly receive greater attention in the clinic. Medical institutions must collaborate to develop standards for cancer screening with attention to the cost-effectiveness of various screening techniques to determine how limited resources can best be spent in cancer control. Such efforts should keep in mind "that a very small change implemented over a broad population may have a greater effect in absolute numbers than a large level of change applied in a small segment of the population."

Thoracoscopic Staging and Surgical Therapy for Esophageal Cancer

Esophageal cancer continues to be a major health problem with an associated poor prognosis. New technology is being applied to the staging of this cancer. The new staging system requires assessment of depth of wall penetration and lymph node status prior to resection. To determine penetration and node status with a high degree of accuracy generally requires some combination of chemotherapy, magnetic resonance imaging, endoesophageal ultrasound, and/or surgical staging. Several variables need to be considered in planning the surgical approach to the patient with esophageal cancer: the intent of the surgeon to either cure or palliate, the anatomic location of the tumor, and the method of reconstruction. Surgery is optimal for localized esophageal cancer. Neoadjuvant chemoradiation has increased survival in specific subgroups. Phase 2 trials have shown the safety and efficacy of chemoradiation. Randomized multi-institutional trials are needed to verify the encouraging results of recent phase 2 trials.