Incidence of Occult Lymph Node Metastases in Pathological Stage C (pT3NO) Prostate Cancer

Impact of five-tiered Gleason grade groups on prognostic prediction in clinical stage T3 prostate cancer undergoing high-dose-rate brachytherapy

BACKGROUND

We evaluated a five-tiered Gleason grade groups arising from the 2014 International Society of Urological Pathology consensus conference on prognostic prediction in clinical stage T3a (extracapsular invasion) and T3b (seminal vesicle involvement) prostate cancer undergoing high-dose-rate brachytherapy (HDR-BT).

METHODS

From November 2003 to December 2012, 283 patients with stage T3 prostate cancer received HDR-BT and external beam radiation therapy (EBRT) with long-term androgen deprivation therapy (ADT). Of these, 203 (72%) and 80 (28%) patients had stage T3a and T3b disease, respectively. The mean dose to 90% of the planning target volume was 7.5 Gy/fraction of HDR-BT. After five fractions, EBRT with 10 fractions of 3 Gy was administered. All patients first underwent ≥6 months of neoadjuvant ADT, and adjuvant ADT continued for 36 months. Median follow-up was 74 months from the start of radiotherapy.

RESULTS

The 10-year biochemical recurrence (BCR) -free rate for stage T3a and T3b disease was 79% and 64%, respectively (P = 0.0083). The 10-year cancer-specific survival (CSS) rate for stage T3a and T3b was 96% and 91%, respectively (P = 0.0305). Although grade groups ≥4 were independent predictors for BCR in cT3a patients (P = 0.0270), they failed to significantly predict prostate cancer-specific mortality (PCSM) among cT3a patients. Among cT3b patients, grade group 5 was a significant predictor of both BCR (P = 0.0017) and PCSM (P = 0.0233). Among stage T3a patients, no significant difference existed in 10-year CSS between grade groups 5 and 4 (94% vs 97%, P = 0.3960). In contrast, grade group 5 had a significantly worse outcome in 10-year CSS than grade group 4 among stage T3b patients (74% vs 100%, P = 0.0350).

CONCLUSIONS

Stage T3a patients with grade groups 4/5 and stage T3b with grade group 4 had fairly low PCSM risk. Approximately one of four patients among stage T3b patients with grade group 5 showed PCSM after combined HDR-BT and EBRT with long-term ADT. Stage T3b patients with grade group 5 may have a greater risk for PCSM.

Detecting metastatic prostate carcinoma in pelvic lymph nodes following neoadjuvant hormone therapy: the eyes have it!

AIMS

Residual cancer morphology in radical prostatectomies (RPs) after neoadjuvant hormone therapy includes inconspicuous cytology, and treated tumour cells can be difficult to identify in lymph nodes. The aim of this study was to evaluate the role of immunohistochemistry (IHC) in identifying occult lymph node metastases following neoadjuvant hormone treatment of prostate cancer.

METHODS AND RESULTS

One hundred and twenty-eight lymph nodes from 24 patients treated with neoadjuvant hormone therapy, including abiraterone acetate alone or combined with leuprolide, were stained with antibodies against keratin AE1/AE3, prostate-specific antigen (PSA), prostate-specific acid phosphatase (PrAP), androgen receptor (AR), and NKX3.1. IHC slides were scored 'blind', and then retrospectively compared with haematoxylin and eosin (H&E)-stained slides and pathology reports. IHC identified carcinoma in six lymph nodes from three patients. All metastases were positive for NKX3.1 and AR, five of six were positive for AE1/AE3, and three of six were positive for PSA; PrAP was negative in all metastatic foci. All six lymph node metastases had been identified by H&E staining at the time of RP.

CONCLUSIONS

These findings suggest that routine use of IHC on lymph nodes from neoadjuvant-treated prostate carcinomas is not necessary. Nevertheless, for suspicious small foci of atypical cells in neoadjuvant-treated lymph nodes, NKX3.1 and AR appear to have the greatest sensitivity.

Histopathological characteristics of lymph node metastases predict cancer-specific survival in node-positive prostate cancer

OBJECTIVE

To correlate the histopathological characteristics of lymph node metastases in prostate cancer with cancer-specific survival (CSS).

PATIENTS AND METHODS

The histopathological slides from 142 patients who had had a pelvic lymph node dissection for node-positive prostate cancer were reviewed. For each patient we recorded the number of lymph nodes removed, the number of positive nodes, the diameter of the largest metastasis and extranodal extension (ENE). The lymph node metastases were graded according to the Gleason system. These variables were correlated with CSS.

RESULTS

The mean age of the patients was 62.4 years and the mean preoperative prostate-specific antigen level was 40.2 ng/mL. The median follow-up was 77.5 months, and the median overall and CSS were 91 and 112 months, respectively. On univariable analysis the following variables correlated with poor CSS: a nodal Gleason score of >7 (hazard ratio 2.4, P < 0.001), a diameter of the largest metastasis of >3 mm (2.2, P = 0.025), more than two lymph node metastases (2.0, P = 0.003), and ENE in more than one lymph node (1.9, P = 0.014). Multivariable analysis showed only the nodal Gleason score and the diameter of the largest metastasis to be independent predictors of CSS (1.8, P = 0.021, and 2.2, P = 0.046, respectively).

CONCLUSION

The histopathological characteristics of lymph node metastases in prostate cancer have predictive value for the clinical outcome. The nodal Gleason score and the diameter of the largest metastasis are independent predictors of survival.

Optimized coverage of high-risk adjuvant lymph node areas in prostate cancer using a sentinel node–based, intensity-modulated radiation therapy technique

PURPOSE

Irradiation of adjuvant lymph nodes in high-risk prostate cancer was shown to be associated with improved rates of biochemical nonevidence of disease in the Radiation Therapy Oncology Group trial (RTOG 94-13). To account for the highly individual lymphatic drainage pattern we tested an intensity-modulated radiation therapy (IMRT) approach based on the determination of pelvic sentinel lymph nodes (SN).

METHODS AND MATERIALS

Patients with a risk of more than 15% lymph node involvement were included. For treatment planning, SN localizations were included into the pelvic clinical target volume. Dose prescriptions were 50.4 Gy to the adjuvant area and 70.0 Gy to the prostate. All treatment plans were generated using equivalent uniform dose (EUD)-based optimization algorithms and Monte Carlo dose calculations and compared with 3D conventional plans.

RESULTS

A total of 25 patients were treated and 142 SN were detectable (mean: n = 5.7; range, 0-13). Most SN were found in the external iliac (35%), the internal iliac (18.3%), and the iliac commune (11.3%) regions. Using a standard CT-based planning target volume, relevant SN would have been missed in 19 of 25 patients, mostly in the presacral/perirectal area (22 SN in 12 patients). The comparison of conventional 3D plans with the respective IMRT plans revealed a clear superiority of the IMRT plans. No gastrointestinal or genitourinary acute toxicity Grade 3 or 4 (RTOG criteria) occurred.

CONCLUSIONS

Distributions of SN are highly variable. Data for SN derived from single photon emission computed tomography are easily integrated into an IMRT-based treatment strategy. By using SN data the probability of a geographic miss is reduced. The use of IMRT allows sparing of normal tissue irradiation.

Current status of lymph node-positive prostate cancer: Incidence and predictors of outcome

In early surgical series, the incidence of positive lymph nodes in patients with prostate cancer was approximately 40%. In the modern era of screening and improved patient selection, the incidence is now <10%, although most series excluded patients with higher risk disease. The risk of having positive lymph nodes is influenced by disease stage, prostate-specific antigen level, and tumor grade and by the aggressiveness of lymph node dissection. Many of the same factors predict the outcome of these patients. Although the percentage of patients with positive lymph nodes has declined, there remain significant numbers of patients with lymph node-positive prostate cancer, and it remains a therapeutic dilemma.

Detection of Occult Lymph Node Metastases in Locally Advanced Node-Negative Prostate Cancer

Purpose

The purpose of this study was to determine the incidence and clinical significance of occult metastases in the lymph nodes of patients with prostate cancer originally considered node negative by routine histologic evaluation.

Methods

Two hundred seventy four patients with pT3 prostate carcinoma treated by radical prostatectomy and bilateral lymph node dissection were included in this study. One hundred eighty patients were staged node negative (N0), while 94 patients were lymph node positive (N+), based on routine histologic evaluation. All lymph nodes from the 180 N0 patients were evaluated for occult metastases by immunohistochemistry using antibodies to cytokeratins and, if positive, prostate-specific antigen. Recurrence and overall survival were compared among patients with occult tumor cells (OLN+), with patients whose lymph nodes remained negative (OLN−), and with the 94 N+ patients.

Results

A total of 3,914 lymph nodes were evaluated from 180 N0 patients (average, 21.7 lymph nodes per patient). Occult tumor cells were found in 24 of 180 patients (13.3%). The presence of OLN+ was significantly associated with increased recurrence and decreased survival compared with OLN− patients (P < .001 and P = .019, respectively; relative risk of recurrence, 2.27; relative risk of death 2.07, respectively). The presence of occult lymph node metastases was an independent predictor of recurrence and death in a multivariable analysis. The outcome for patients with OLN+ disease was similar to that for patients with N+ disease.

Conclusion

The detection of occult lymph node metastases in patients with pT3N0 prostate cancer identifies those with significantly increased risk of prostate cancer recurrence and death.

The role of whole pelvic radiotherapy in locally advanced prostate cancer

Routine PSA testing has led to diagnosis and treatment of prostate cancer at earlier stages than previously. Earlier and technically-improved treatment, together with escalation of dose has enhanced cure rates. Although, the incidence of nodal metastases is now lower than in pre-PSA days, more extended pelvic lymphadenectomies have shown the actual rate of lymph node involvement to be higher than had been determined from standard radical prostate surgery. As in cancers in other sites, especially in their earlier stages, lymph node metastases may exist in the absence of haematogenous dissemination. This, together with the improved rates of control of the primary prostate tumour, suggests that elective irradiation of early-stage lymph nodes from prostate cancer should enhance survival in a manner analogous to improvements seen with this approach in other cancers. Although, the absolute incidence of positive nodes in locally advanced prostate cancer warrants elective radiotherapy, it is relatively low and the modest improvements to be expected may be undetected in the results of a small trial.

Radiotherapy in the Management of Clinically Localized Prostate Cancer: Evolving Standards, Consensus, Controversies and New Directions

Major advances have been made in the definitive use of various forms of radiotherapy (RT) in the management of clinically localized prostate cancer (PCa). Despite tremendous gains, the radiation oncology community continues to struggle with several key questions. In general, the areas of controversy pertain to how to improve the therapeutic ratio of RT. Specifically, key issues include dose escalation; the relative benefit of alternative forms of RT (ie, brachytherapy and protons); target localization; the use, timing, and duration of androgen deprivation; and the need for pelvic nodal irradiation. Multiple efforts have been made to address each of these issues; however, there is no consensus on how to resolve them. This review is an evidence-based critique of the available treatment approaches considered for the optimal use of radiotherapy as definitive management of clinically localized PCa.

Cytokeratin staining of resected lymph nodes may improve the sensitivity of surgical staging for endometrial cancer

OBJECTIVE

The presence of metastases to regional lymph nodes (LN) is the single most important risk factor in endometrial cancer. Advances in molecular biology have provided more sensitive methods for detecting micrometastasis. This was a pilot study to determine whether cytokeratin staining of LN from endometrial cancer patients is more sensitive than traditional histopathologic evaluation for the detection of micrometastasis.

METHODS

The inclusion criteria included patients with surgical stage I-II endometrial cancer having >50% myometrial invasion, lesions >2 cm, and negative LN together with one of the following: FIGO grade 3 or cervical or lymph-vascular involvement. A matched control group included patients with LN metastasis. The evaluation of the LN at the time of initial surgery consisted of a frozen section and a reevaluation on permanent sections with H&E. In the study, lymphadenectomy specimens were cut, stained again with H&E and with cytokeratin, and examined. Cytokeratin staining was performed with AE1/AE3 antibodies. There were 16 LN-negative cases and 9 LN-positive controls.

RESULTS

There was complete agreement between the LN assessment at time of surgery and the study H&E review prior to the staining for cytokeratin. However, 2 LN-negative cases (12.5%) had micrometastasis by cytokeratin staining. One of these patients developed recurrent disease in the para-aortic LN and died of disease at 2.8 years.

CONCLUSION

Cytokeratin staining may improve the sensitivity for detection of metastasis compared to traditional evaluation. This study strongly suggests that these micrometastasis are clinically significant. An approach incorporating cytokeratin analysis could improve the risk assessment of specific patients.

Detection of clinically significant, occult prostate cancer metastases in lymph nodes using a splice variant-specific rt-PCR assay for human glandular kallikrein

PURPOSE

To compare the detection of human glandular kallikrein 2 (hK2) mRNA expression in archival lymph nodes with disease progression, the development of prostate cancer metastases, and mortality in patients undergoing radical prostatectomy for locally advanced nonmetastatic prostate cancer.

PATIENTS AND METHODS

We evaluated total RNA extracted from fixed, paraffin-embedded, histopathologically normal pelvic lymph nodes, removed at radical prostatectomy, from 199 pT3N0 prostate cancer patients (150 extraprostatic extension only; 49 seminal vesicle involvement) for hK2-expressing cells using a novel reverse transcriptase polymerase chain reaction (RT-PCR)/hK2 assay. Cumulative incidence functions and Cox proportional hazards analyses were performed.

RESULTS

Forty patients (20%) had positive results, 80 patients (40%) had negative results, and 79 patients (40%) had equivocal results. RT-PCR/hK2 status was not associated with any pathologic characteristics (P >.05). In postoperative multivariable models, the RT-PCR/hK2 result was associated with prostate cancer progression (P =.001), development of distant metastases (P =.001), and prostate cancer-specific survival (P =.005). In patients experiencing biochemical progression (n = 33), RT-PCR/hK2 status was a predictor of failure to respond to salvage radiotherapy (P =.002).

CONCLUSION

RT-PCR/hK2 can detect biologically and clinically significant occult prostate cancer metastases in histopathologically normal lymph nodes. In patients with locally advanced prostate cancer, RT-PCR/hK2 is strongly associated with prostate cancer progression, failure following salvage radiation therapy, development of clinically evident metastases, and prostate cancer-specific mortality after surgery.

The influence of serial sections, immunohistochemistry, and extension of pelvic lymph node dissection on the lymph node status in clinically localized prostate cancer

OBJECTIVES

Pelvic lymph node metastases indicate a poor prognosis for patients with clinically localized prostate cancer. The aim of the study was to investigate the value of extended histopathological techniques considering the extent of pelvic lymphadenectomy and preoperative risk factors.

METHODS

Total of 194 patients with prostate cancer were examined. At first all patients had a sampling of the sentinel lymph nodes (SLN) followed in most cases by a modified or extended pelvic lymphadenectomy. Step sections, serial sections and immunohistochemistry (IHC, pancytokeratin antibody) were analyzed in all SLN and so-called non-SLN of the first 100 patients. Later serial sections and IHC of non-SLN were left out.

RESULTS

In 26.8% lymphatic metastases were found. The detection rate of lymph node-positive patients depend significantly on the chosen extension of pelvic lymphadenectomy. Limiting the histopathological investigation to the lymph node specimen of the obturator fossa only 44.2% of lymph node-positive cases would have been identified. An additional inclusion of all lymph nodes surrounding the external iliac vessels improves the sensitivity to 65.4% (46.7% and 73.3% for the first 100 patients). Compared to the extension of pelvic lymphadenectomy the diagnostic gain of serial section and IHC (13.8% versus 53.3%) was comparably low.

CONCLUSIONS

The extension of pelvic lymph node dissection is of outstanding value for the identification of node-positive patients. Limiting the number of lymph nodes to the ones with the highest probability of bearing lymphatic spread (SLN) makes the use of extensive histopathological techniques more feasible.

Characterization of disseminated tumor cells

The most prominent secondary organs screened for the presence of occult disseminated tumor cells are regional lymph nodes and bone marrow. The current data suggest that micrometastatic cells represent a selected population of dormant cancer cells, which still express a considerable degree of heterogeneity. The analysis of micrometastatic cells will open a new avenue to assess the molecular determinants of both early tumor cell dissemination and subsequent outgrowth into overt metastases. Moreover, identifying therapeutic target structures (e.g., HER2), monitoring the elimination of bone marrow micrometastases, and assessing treatment-resistant tumor cell clones may help in understanding the current limitations of adjuvant systemic therapy. This review summarizes the current knowledge on the biological characteristics of micrometastatic cancer cells in bone marrow and lymph nodes of cancer patients.

Occult metastasis

The most important factor affecting the outcome of patients with invasive cancers is whether the tumor has spread, either regionally (to regional lymph nodes) or systemically. However, a proportion of patients with no evidence of systemic dissemination will develop recurrent disease after primary 'curative' therapy. Clearly, these patients had occult systemic spread of disease that was undetectable by methods routinely employed (careful pathological, clinical, biochemical and radiological evaluation). In addition, the success of adjuvant therapy is assumed to stem from its ability to eradicate occult metastases before they become clinically evident [1]. Therefore, methods for the detection of occult metastases in patients with the earliest stage of cancer, i.e., prior to detection of metastases by any other clinical or pathological analysis, have received a great deal of attention.

Lymph Node Micrometastases in Non–Small-Cell Lung Cancer: Clinical Applications

A large number of patients are diagnosed every year with non small-cell lung cancer, and their prognosis and response to treatment are inversely correlated to tumor stage at initial diagnosis. Despite the surgical removal of all apparent malignancy from patients with early disease, many will relapse, presumably as a result of disease that was undetected at initial evaluation. In an effort to identify those patients who have early lymph node involvement by metastatic disease, several groups of investigators have searched for the presence of micrometastases in hematoxylin-eosin-negative lymph nodes using immunohistochemical or molecular methods. Four of six groups of investigators using immunohistochemistry have found a significant incidence of lymph node micrometastases and a direct correlation between the absence of micrometastases and disease-free survival; these are encouraging results that require confirmatory studies. Molecular methods may potentially offer increased sensitivity; however, their high cost and the requirement to process large numbers of samples limits their use to research settings at present.

Value of reverse transcription polymerase chain reaction assay in pathological stage T3N0 prostate cancer

BACKGROUND

We tested the ability of the nested reverse transcription polymerase chain reaction (RT-PCR) assay to detect signs of biochemical recurrence of prostate cancer in the lymph nodes and peripheral blood of patients with pT3N0 prostate cancer.

METHODS

Using lymph nodes and pre- and postoperative peripheral blood dissected from 30 patients with pT3N0 prostate cancer treated by radical prostatectomy, we used RT-PCR for prostate-specific membrane antigen (PSM) and serum prostate-specific antigen (PSA) to determine the presence of prostate cancer. Results of the nested RT-PCR assay were compared with pathological stages and biochemical recurrence.

RESULTS

Two of 13 patients with capsular penetration (15%), 6 of 10 patients with invasion of seminal vesicles (60%), and 3 of 7 patients with a positive surgical margin (43%) were RT-PCR-positive for PSM and/or PSA in the lymph nodes. Results of preoperative RT-PCRs of peripheral blood for PSM and for PSA significantly differed between positive and negative results of RT-PCR in lymph nodes (P < 0.001 and P < 0.001, respectively). Results of postoperative RT-PCRs of peripheral blood for PSM and for PSA also significantly different between positive and negative results of RT-PCR in lymph nodes (P = 0.011 and P = 0.001, respectively). Nine of 11 patients with positive nested RT-PCR for PSM and/or PSA in the lymph nodes (82%) experienced biochemical recurrence. Significant difference in Kaplan-Meier recurrence-free actuarial curves was noted between patients who nested positive and negative on RT-PCR in the lymph nodes, pre- and postoperative peripheral blood, biopsy and prostatectomy Gleason score, and preoperative PSA values. In multivariate analysis, biopsy and prostatectomy Gleason score (P = 0.026, P = 0.020, respectively), pre- and postoperative RT-PCR for PSM in peripheral blood (P = 0.030 and P = 0.040, respectively), and RT-PCR for PSM in lymph nodes (P = 0.035) were independent prognostic factors.

CONCLUSIONS

Nested RT-PCR assay of the lymph nodes or peripheral blood significantly predicted biochemical recurrence after surgery. It may help identify patients at risk for recurrence and progression of prostate cancer.

The immunohistochemical assessment of occult regional lymph node metastases in patients with T3pN0M0 prostate cancer before definitive radiotherapy

OBJECTIVE

To detect occult regional lymph node metastases in patients with T3pN0M0 prostate cancer not recognized by routine haematoxylin and eosin staining, and to evaluate the clinical relevance of this finding.

PATIENTS AND METHODS

Formalin-fixed and paraffin-embedded pelvic lymph nodes (1118) from 92 patients were evaluated by immunohistochemistry using antibodies for prostate specific antigen (PSA) and pancytokeratin (AE1/AE3). Of the tumours, 14% were well, 69% moderately and 17% poorly differentiated. The extent of tumour was categorized as T3pN0M0 in all patients, who were referred for definitive radiotherapy after pelvic staging lymphadenectomy. The median (range) serum PSA value before treatment was 18.5 (0.4-342) microg/L. After radiotherapy, the patients were followed by assessing biochemical progression, pelvic recurrence and/or development of distant metastases. The median (range) observation time for all patients was 61 (16-136) months.

RESULTS

Occult lymph node metastases were detected in four (4.4%) of the 92 patients. Patients with or without occult metastases had similar serum PSA levels and histological grades. None of the four patients with occult metastases progressed, compared with 37 of the 88 (42%) with no such metastases.

CONCLUSION

Using immunohistochemistry the detection rate of occult lymph node metastases in patients with T3pN0M0 prostate cancer is low. The occurrence of such metastases is probably unrelated to the serum PSA value before treatment. The short-term outcome of patients subsequently treated with definitive radiotherapy does not seem to be associated with the finding of occult lymph node metastases, but long-term follow-up is needed. So far, the results do not justify the search for occult lymph node metastases as a routine procedure in these patients

Treatment of locally advanced prostate cancer: is chemotherapy the next step?

PURPOSE

Management of locally advanced prostate cancer remains controversial. Various single and combination modality approaches have been advocated, but an accepted standard of care remains undefined. The purpose of this review is to define the current knowledge in managing locally advanced prostate cancer and to propose new treatment approaches based on current knowledge.

MATERIALS AND METHODS

A MEDLINE search to detect all relevant articles on the management of locally advanced prostate cancer was performed. A review of the staging, natural history, and prognosis of this disease was also performed.

RESULTS

The lack of a clearly defined treatment approach to patients with locally advanced prostate cancer stems from multiple factors, including ambiguities in clinical staging, inadequate knowledge of the natural history of the cancer, and a dearth of comparative randomized trials evaluating efficacy of different therapies. Single modality treatment, including radical prostatectomy (RP) or external-beam radiotherapy alone, is associated with high rates of failure. The use of adjuvant hormonal ablation therapy in combination with external-beam radiotherapy has shown improvement in progression-free and overall survival, although similar improvements have not been clearly demonstrated for surgical patients treated with hormonal therapy. New advances in chemotherapy for hormone-refractory prostate cancer suggest that response rates may be as high as 50% or more, and current trials are evaluating the addition of chemotherapy to hormonal ablation in either surgery or radiation therapy in locally advanced prostate cancer.

CONCLUSION

Optimal management of locally advanced prostate cancer remains undefined. Standard treatment options include RP, external-beam radiotherapy, or hormonal ablation therapy, alone or in combination. New approaches being tested include improved methods for delivering radiation or combining hormonal ablation with surgery or radiation. It is possible that other forms of systemic therapy, including chemotherapy, may become important components of multimodality treatment. Clinical trials designed to test this hypothesis are ongoing.

Detection and clinical importance of micrometastatic disease

Metastatic relapse in patients with solid tumors is caused by systemic preoperative or perioperative dissemination of tumor cells. The presence of individual tumor cells in bone marrow and in peripheral blood can be detected by immunologic or molecular methods and is being regarded increasingly as a clinically relevant prognostic factor. Because the goal of adjuvant therapy is the eradication of occult micrometastatic tumor cells before metastatic disease becomes clinically evident, the early detection of micrometastases could identify the patients who are most (and least) likely to benefit from adjuvant therapy. In addition, more sensitive methods for detecting such cells should increase knowledge about the biologic mechanisms of metastasis and improve the diagnosis and treatment of micrometastatic disease. In contrast to solid metastatic tumors, micrometastatic tumor cells are appropriate targets for intravenously applied agents because macromolecules and immunocompetent effector cells should have access to the tumor cells. Because the majority of micrometastatic tumor cells may be nonproliferative (G0 phase), standard cytotoxic chemotherapies aimed at proliferating cells may be less effective, which might explain, in part, the failure of chemotherapy. Thus, adjuvant therapies that are aimed at dividing and quiescent cells, such as antibody-based therapies, are of considerable interest. From a literature search that used the databases MEDLINE(R), CANCERLIT(R), Biosis(R), Embase(R), and SciSearch(R), we discuss the current state of research on minimal residual cancer in patients with epithelial tumors and the diagnostic and clinical implications of these findings.

Comparative immunocytochemical assessment of isolated carcinoma cells in lymph nodes and bone marrow of patients with clinically localized prostate cancer

After radical prostatectomy for clinically localized prostate cancer, biochemical progression is seen in up to 40% of the patients due to persistent local and/or systemic remnants. Isolated disseminated carcinoma cells, undetectable by current staging methods, are of special interest as potential precursors of subsequent overt metastases. In the present study, immunohistochemistry (IHC) was performed to evaluate simultaneously the frequency of occult carcinoma cells in both lymph nodes (LNs) and bone marrow (BM) obtained from the iliac crests of 45 prostate cancer patients with untreated stage T(1-3) pN0 M0 prostatic carcinoma. IHC using monoclonal antibodies (MAbs) against epithelial cytokeratins was performed on 521 paraffin-embedded LNs histopathologically classified as tumorfree (pN0), as well as on BM cytospin preparations. To confirm the prostatic origin of positive cells in LNs, additional IHCs for prostate-specific antigen (PSA) and epithelial glycoproteins were performed. In total, isolated tumor cells in LNs and/or BM were detected in 17 of the 45 patients. Parameters such as tumor stage, grade and volume of the primary tumor as well as blood serum PSA levels could not detect patients harboring disseminated single tumor cells in LNs or BM. Following a median observation time of 24.9 months, no significant correlation between IHC positivity and PSA progression as a measure of early relapse was observed. Although the overall incidence of occult tumor cell spread corresponds to similar incidence of relapses after radical prostatectomy as reported by others, the fate of these cells needs to be evaluated in longer follow-up studies.

Detection of occult metastases in lung carcinomas: progress and implications for lung cancer staging

The ability to detect occult regional and systemic metastases in patients with operable lung carcinoma could have a significant impact on the management of the disease. Here, we review the literature, including studies from our own laboratory, regarding the clinical significance of the presence of occult metastases in patients with lung cancer. The accumulated evidence strongly suggests that the detection of occult regional and systemic metastases is an important predictor of disease progression. The use of this method should be considered in the future design of lung cancer clinical trials, at the very least. The detection of occult metastases should have an impact on lung cancer management; to reflect this, we propose a change in the TNM staging system to indicate the presence or absence of occult regional (lymph node) and systemic (bone marrow) metastases. The proposed change is TNnMm, where n and m are occult nodal and bone marrow metastases status.

Cancer volume of lymph node metastasis predicts progression in prostate cancer

Clinical outcome is variable in prostate cancer patients with regional lymph node metastasis. We studied 269 patients who had regional lymph node metastasis at the time of radical retropubic prostatectomy and bilateral pelvic lymphadenectomy at the Mayo Clinic between January 1987 and December 1992. Two hundred fifty-three (94%) patients received androgen deprivation therapy within 90 days of radical prostatectomy. Patients ranged in age from 47 to 79 years (median, 67 years). Median follow-up was 6.1 years (range, 0.3-10.5 years). Nodal cancer volume (size) was measured by the grid-counting method. Cox proportional hazards models were used to determine the impact of numerous clinical and pathologic findings on systemic progression-free survival. Systemic progression was defined as the presence of distant metastasis documented by biopsies or radiographic examinations (abdominal computerized tomography, plain radiographs, or bone scan). Five-year progression-free survival was 90%. In predicting systemic progression using Cox multivariate analysis, only nodal cancer volume added significantly to the model containing the primary cancer variables (Gleason score, cancer volume, and DNA ploidy). The relative hazard rate for a doubling in nodal cancer volume was 1.6 (95% confidence interval, 1.3 to 2.0; p < 0.0001). Spearman rank analysis showed a correlation between nodal cancer volume and Gleason score of the primary cancer, the number of positive nodes, the aggregate length of metastases, and the largest nodal cancer diameter (correlation efficient = 0.37, 0.63, 0.96, and 0.95, respectively). Our data indicate that nodal cancer volume was the most significant nodal determinant of progression to distant metastasis in lymph node-positive prostate cancer patients. We recommend that the diameter of the largest metastasis be evaluated in patients with metastases, because this is a more powerful predictor of patient outcome than current methods, which recommend mere counting of the number of positive nodes.

Improved freedom from PSA failure with whole pelvic irradiation for high-risk prostate cancer

PURPOSE

To determine the impact of whole pelvic irradiation on the risk of PSA failure in prostate cancer patients, at high predicted risk for lymph node involvement, receiving definitive radiotherapy.

MATERIALS AND METHODS

Between October 1987 and December 1995, 506 patients with clinically localized prostate cancer were treated with definitive radiotherapy at UCSF and affiliated institutions. Treatment consisted of 4-field whole pelvic irradiation followed by a prostate-only boost, or prostate-only treatment (median follow-up was 35 months and 30 months, respectively). PSA failure was defined as: 1. a PSA value > or = 1 ng/ml; or 2. a PSA value that rose > or = 0.5 ng/ml in < or = 1 year posttreatment on two consecutive measurements, with the first rise defined as the time of failure. The calculated risk of lymph node positivity (%rLN+) was defined as 2/3(iPSA) + 10(GS-6), and high risk was defined as %rLN+ > or = 15%. Univariate and multivariate analyses were performed.

RESULTS

A total of 201 high-risk patients were identified. High-risk patients who received whole pelvic irradiation had significantly improved freedom from PSA failure compared to those who received prostate-only treatment (median PFS = 34.3 months vs. 21.0 months; p = 0.0001). Potential confounding variables, including initial PSA, Gleason score, T stage, radiation dose, year of treatment, use of three-dimensional (3D) conformal techniques, and use of hormone therapy, did not account for the observed difference in time to PSA failure. Multivariate analysis revealed type of radiation treatment to be the most significant independent predictor of outcome.

CONCLUSION

Whole pelvic radiotherapy significantly improves the PSA failure-free survival in patients with a high calculated risk of lymph node positivity.

Prospective analysis of prostate-specific markers in pelvic lymph nodes of patients with high-risk prostate cancer

BACKGROUND

Pathologic evidence of pelvic lymph node involvement is obtained in 12%-20% of patients with localized prostate cancer that exhibits high-risk features (defined on the basis of tumor size, serum prostate-specific antigen [PSA] level, or Gleason score). The rate of systemic failure (i.e., relapse) in patients with this type of prostate cancer and no pathologic evidence of regional lymph node involvement is 55%-92% within 5 years of definitive local therapy. Since reverse transcription-polymerase chain reaction (RT-PCR) methods are likely to be more sensitive than routine pathologic examination in detecting metastatic tumor cells, we compared the ability of the two approaches to detect prostate cells in the pelvic lymph nodes of patients with localized, high-risk disease.

METHODS

Fifty-eight lymph node specimens isolated from 33 patients before definitive local therapy were examined. Expression of PSA and prostate-specific membrane antigen (PSM) messenger RNAs in the specimens was assessed by means of nested RT-PCR.

RESULTS

Pathologic examination identified tumor cells in the lymph nodes of four (12%) of the 33 patients, and PSA and/ or PSM expression was positive in specimens from 27 (82%) of the patients (two-sided P<.0001). The four patients with positive pathologic findings also had positive RT-PCR results. Among the 29 patients with no pathologic evidence of lymph node involvement, 23 (79%) tested positive by means of RT-PCR. In these 23 patients, PSM expression was detected more frequently than PSA expression; however, in two patients, only PSA expression was detected.

CONCLUSIONS

Expression of prostate-specific markers in the pelvic lymph nodes of patients with localized, high-risk prostate cancer may indicate the presence of metastatic tumor cells. Such cells may be responsible for the high rate of systemic failure seen in these patients. Additional studies are required to determine the prognostic relevance of our findings.

The status of immunohistochemical studies in lymphoma diagnosis

Immunohistochemical studies of formalin fixed paraffin embedded sections today constitute an essential component of the diagnostic process for malignant lymphoma. Lineage related markers are of value in distinguishing various lymphomas from anaplastic large and small cell carcinomas, and from sarcomas. Other more recently available markers are of value in establishing prognosis and, on occasion, in differentiating between neoplastic and reactive proliferations. Meticulous attention to reagent control and technical procedures is essential to all such studies.

Anatomical basis for pelvic lymphadenectomy in prostate cancer: results of an autopsy study and implications for the clinic

PURPOSE

Pelvic lymphadenectomy remains the most reliable method to prove lymph node metastases in prostate cancer. However, evaluation of lymphadenectomy to be complete and sufficient as judged by the number of removed lymph nodes in hampered by the fact that, in contrast to other malignancies (for example breast or gastric cancer), anatomical studies investigating the regular and average number of pelvic lymph nodes are missing. We established an anatomically based standard for pelvic lymphadenectomy.

MATERIALS AND METHODS

Standard pelvic lymphadenectomy was performed on 30 human cadavers and 59 consecutive patients with clinically organ confined prostate cancer during radical retropubic prostatectomy. Number, size and topography of the lymph nodes were noted separately for each anatomical region of both iliac fossas.

RESULTS

The mean number of lymph nodes removed in the autopsy series plus or minus standard deviation (22.7 +/- 10.2, range 8 to 56) was nearly identical to that from patients with prostate cancer (20.5 +/- 6.6, range 10 to 37) but striking interindividual differences were observed. Patients with prostate cancer demonstrated enlarged nodes regardless of whether they did or did not contain tumor. Interestingly, pelvic lymph node metastases were more common on the left side regardless of the primary tumor site.

CONCLUSIONS

Approximately 20 pelvic lymph nodes may serve as a guideline for a sufficient standard pelvic lymph node dissection. Lymphadenopathy in prostate cancer patients is not always a result of metastases but, rather, hyperplastic or regressive alterations. A preferential distribution of lymph node metastases along the left iliac vessels regardless of the primary tumor site in the prostate warrants further investigation.