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D Kuban

Publications and source records attributed to D Kuban.

7 recordsLinked to original sources
PubMed2001

Clinical staging of prostate cancer: reproducibility and clarification of issues.

The American Joint Committee on Cancer (AJCC) staging system for prostate cancer adopted in 1992 is based on tumor-node-metastasis (TNM) designations. It has been widely accepted for use in local and advanced disease. The purpose of this study was to assess reproducibility of staging among observers and to help clarify staging issues. Twelve prostate cancer cases were sent to 20 physicians with special expertise in prostate cancer including eight urologists, eight radiation oncologists, and four medical oncologists. Physicians were asked to assign a stage based on the 1992 AJCC clinical staging. The most frequently reported stage assigned to each case was taken to be the consensus. Agreement was the percentage of physicians who reported that particular stage. Seventy-five percent of the physicians responded. The overall agreement for assignment of T stage was 63.9%. Differences were found by specialty for inclusion of available information in designating a T stage. The overall agreement for N stage was 73.8%. The most common designation was Nx regardless of availability of a computed tomography scan. The overall agreement for M stage was 76.6%. Without a bone scan the most common designation was Mx regardless of Gleason grade or prostate-specific antigen (PSA). A frequent comment was that PSA was more indicative of disease extent than current clinical staging. The reproducibility of the 1992 clinical AJCC staging is poor even among experts in the field. This problem arises primarily from disagreement regarding which studies are included in assigning a stage. Some of these difficulties are addressed in the 1997 revision. However, the clinical staging does not address the true biological significance of disease in many instances.

Humans↗
PubMed2000

Fifteen-year minimum follow-up of a prostate brachytherapy series: comparing the past with the present.

OBJECTIVES: To report the overall survival for 126 patients more than 15 years after iodine-125 interstitial therapy; to report the biochemical progression status for those alive and clinically without evidence of disease for longer than 15 years; to document the upward migration of grade by date of grade assignment; to compare the tumor stage and grade profile of this mature series with our current experience; and to clarify the prostate-specific antigen (PSA) data when this series is used as a historical comparison. METHODS: The records of 126 patients who underwent interstitial therapy more than 15 years previously were reviewed for assessment of the current TNM stage and Gleason grade and the current PSA level for patients clinically free of disease. The tumor grade and stage of these patients were compared with those of the first 126 patients treated by transrectal ultrasound-guided brachymonotherapy at our center between January 1995 and January 1999. The methodology of our 1993 publication was also reviewed. RESULTS: Of the 16 patients clinically free of disease (13 still alive and 3 dead of other causes more than 15 years after therapy), a review of the initial diagnostic needle biopsy was unable to confirm the presence of tumor in 3 patients. Of the remaining 13, 4 had a PSA level of 0.2 ng/mL or less, 4 a PSA level between 0.21 and 0.9 ng/mL, and 5 a PSA level between 1 and 2.5 ng/mL. Re-evaluation of the histopathologic findings using current criteria increased the Gleason score and World Health Organization grade. Patients currently selected for brachytherapy have a lower Gleason grade and TNM stage than recorded for patients treated in the past. The actuarial progression probability curves using the 0.5 or less cutpoint published in 1993 represented the best possible outcome and cannot serve as a historical control for current series comparisons. CONCLUSIONS: For patients who were alive and clinically free of disease longer than 15 years after therapy, the biochemical PSA levels were low. This may be attributed to the therapeutic radiation effect. Whether the improved technology of current transrectal ultrasound-guided implants can extend these favorable results from a small minority to a significant majority and whether it can approach the therapeutic results of radical prostatectomy may be partially answered with a longer follow-up of the current series. The histopathologic criteria have been refined, and upgrading from the initially assigned grade is common. In some cases, a prostate cancer diagnosis could not be confirmed. These findings limit the ability to match patients across time and institution. The results of our 1993 report of biochemical chemical progression-free probability 10 years after iodine-125 implantation cannot be used as a comparator for current studies. Ultimately, a valid comparison between treatment options will only be achieved through a randomized controlled trial.

Brachytherapy↗
PubMed1999

The durability of external beam radiation therapy for prostate cancer: can it be identified?

PURPOSE: We establish criteria to identify a durable response to external beam radiation therapy by calculation of biochemical progression-free probability for patients who attained and maintained defined nadir prostate specific antigen (PSA) levels more than 5 years after treatment. MATERIALS AND METHODS: A total of 460 patients were treated with external beam radiation monotherapy from 1976 to 1995. Patients with PSA less than 0.5 (group 1) or 0.5 to 1.0 (group 2) ng./ml. more than 5 years after treatment were identified. Treatment failure was defined as 3 consecutive increases in PSA after nadir. Progression-free probability after 60 months was calculated for each group. A comparison was also made to patients achieving the same nadir levels anytime after treatment. RESULTS: Failure occurred at 133 months in 1 of 26 group 1 patients (4%) and at a median of 76 months in 5 of 26 group 2 patients (19%). At 10 years progression-free probability was 91% for group 1 compared to 72% for group 2 (p = 0.0575). These same nadir levels anytime after treatment were associated with higher failure rates of 55% for group 1 and 72% for group 2. CONCLUSIONS: If a PSA nadir of less than 0.5 ng./ml. was maintained 5 years after therapy, subsequent failure was rare. Although statistical significance was not reached (p = 0.0575), a higher failure rate was noted if the nadir PSA was 0.5 to 1.0 ng./ml. at 5 years. Thus, patients with PSA 0.5 to 1.0 ng./ml. require careful continued surveillance. Nadir levels less than 1.0 ng./ml. anytime before 5 years were associated with a substantial risk of subsequent progression.

Disease Progression↗
PubMed1996

Breast cancer during pregnancy: quantifying the risk of treatment delay.

OBJECTIVE: To quantify the risk of axillary nodal metastases due to delayed treatment of breast cancer during pregnancy. METHODS: A mathematical model using recently published data was developed to correlate primary breast tumor size with the percentage of pathologically positive axillary lymph nodes. Using this relationship obtained from pathologic data and the accepted relationship of tumor growth and time, Y2 = Y1e(In2)n/DT, an equation estimating the increased risk of axillary metastases due to each day of treatment delay was derived: delta X = 3.7 n/DT, where X = percent positive axillary lymph nodes, n = number of days delay in treatment, and DT = tumor doubling time. RESULTS: A 1-month delay in treatment for an early-stage primary breast cancer with a 130-day doubling time increases the risk of axillary lymph node involvement by 0.9%. A 3-month delay increases the risk by 2.6%, and a 6-month delay by 5.1%. For breast cancer with a 65-day doubling time, a 1-month delay increases the risk by 1.8%, a 3-month delay by 5.2%, and a 6-month delay by 10.2%. CONCLUSION: Axillary lymph nodes are the most important prognostic indicator for survival in breast cancer. Our mathematical model suggests the daily increased risk of axillary metastases due to treatment delay is 0.028% for tumors with moderate doubling times of 130 days and 0.057% for tumors with rapid doubling times of 65 days. This minimal maternal risk may be acceptable to some third-trimester pregnant women with early breast cancer, who prefer organ-sparing treatment with radiation after delivery to a mastectomy during pregnancy. This model further quantitates the increased risk of mortality borne by pregnant women whose breast cancer diagnosis is delayed.

Axilla↗
PubMed1987

Lymphocyte subpopulation profiles and mitogen kinetics in immunological deficiency testing.

The correlation between lymphocyte proliferative responses to mitogens and T4/T8 ratios was analyzed in a cross section of patients who either were in a high-risk group for HTLV-III infection or fulfilled clinical criteria for acquired immune deficiency syndrome (AIDS). The patient results showed that, correlated with decreased T4/T8 ratios, there was a decrease in mitogen responsiveness first to pokeweed mitogen (PWM), followed by concanavalin A (Con A) and then phytohemagglutinin (PHA). Parallel to this decrease there was a shift toward higher concentrations of mitogens needed for optimal proliferation. In comparison, depletion of T4+ lymphocytes from normal healthy controls also decreased lymphocyte proliferative responses to all three mitogens but shifted the amount of mitogen needed for optimal proliferation toward lower concentrations. The differences in mitogen-induced proliferation between patients and healthy controls suggest a model whereby there is a functional defect(s) in mitogen responsiveness of the remaining T4- lymphocyte population that can be overcome when higher concentrations of mitogen are used.

Acquired Immunodeficiency Syndrome↗