Kinetic analysis of recurrence and survival after potentially curative resection of nonsmall cell lung cancer

Neuroimmune Regulation of Surgery-Associated Metastases

Surgery remains an essential therapeutic approach for most solid malignancies. Although for more than a century accumulating clinical and experimental data have indicated that surgical procedures themselves may promote the appearance and progression of recurrent and metastatic lesions, only in recent years has renewed interest been taken in the mechanism by which metastasizing of cancer occurs following operative procedures. It is well proven now that surgery constitutes a risk factor for the promotion of pre-existing, possibly dormant micrometastases and the acceleration of new metastases through several mechanisms, including the release of neuroendocrine and stress hormones and wound healing pathway-associated immunosuppression, neovascularization, and tissue remodeling. These postoperative consequences synergistically facilitate the establishment of new metastases and the development of pre-existing micrometastases. While only in recent years the role of the peripheral nervous system has been recognized as another contributor to cancer development and metastasis, little is known about the contribution of tumor-associated neuronal and neuroglial elements in the metastatic disease related to surgical trauma and wound healing. Specifically, although numerous clinical and experimental data suggest that biopsy- and surgery-induced wound healing can promote survival and metastatic spread of residual and dormant malignant cells, the involvement of the tumor-associated neuroglial cells in the formation of metastases following tissue injury has not been well understood. Understanding the clinical significance and underlying mechanisms of neuroimmune regulation of surgery-associated metastasis will not only advance the field of neuro–immuno–oncology and contribute to basic science and translational oncology research but will also produce a strong foundation for developing novel mechanism-based therapeutic approaches that may protect patients against the oncologically adverse effects of primary tumor biopsy and excision.

Predictors of post-recurrence survival in patients with non-small-cell lung cancer initially completely resected

OBJECTIVES

Despite recent progress in diagnostic technology and therapeutic approaches to non-small-cell lung cancer (NSCLC), 30-75% of patients develop tumour recurrence after resection. However, the details of post-recurrence survival (PRS) are not well understood. We aimed to investigate the predictors of PRS in patients with NSCLC initially completely resected.

METHODS

A series of 568 NSCLC patients who had undergone complete resection between 2000 and 2009 were evaluated retrospectively. Patients who had developed recurrent NSCLC after complete resection were subjected to the current analysis. We examined PRS using the Kaplan-Meier method and multivariate Cox regression analyses.

RESULTS

Of the 568 patients, 138 (24.3%) were identified as having disease recurrence. The 2-year and 5-year PRS rates were 44.6 and 25.9%, respectively, while the median PRS time was 22.5 months. Non-adenocarcinoma histology [hazard ratio (HR) = 2.825, 95% confidence interval (CI): 1.825-4.367, P < 0.001], serum carcinoembryonic antigen (CEA) at recurrence ≥5.0 mg/dl (HR = 2.205, 95% CI: 1.453-3.344, P < 0.001) and no systemic chemotherapy (HR = 2.137, 95% CI: 1.304-3.247, P = 0.002) were independent prognostic factors for PRS.

CONCLUSIONS

The current results showed that non-adenocarcinoma histology, elevated serum CEA at recurrence and no systemic chemotherapy were independent unfavourable post-recurrence prognostic factors. The current data can be informative for patient follow-up after complete resection and further clinical investigation may give us more information about PRS and accurate treatment strategy for recurrent NSCLC after initial complete resection.

Prognosis of recurrent non-small cell lung cancer following complete resection

Prognosis following recurrence subsequent to complete resection of non-small-cell lung cancer (NSCLC) is considered a multifactorial process dependent on clinicopathological, biological and treatment characteristics. Gefitinib was approved for lung cancer treatment in Japan in 2002. The aim of the current study was to quantify the prognostic effects of these characteristics on post-recurrence prognosis. In total, 127 NSCLC patients were analyzed who underwent complete resection and subsequently had recurrent cancer. The correlation between characteristics of the initial and recurrent disease with post-recurrence prognosis was investigated. The factors clearly associated with post-recurrence prognosis using Cox proportional hazards models were age at recurrence (those <65 years of age typically had better prognoses) and interval between initial resection and recurrence (intervals of <1 year accompanied a worse prognosis). Epidermal growth factor receptor (EGFR) mutant patients treated with EGFR tyrosine kinase inhibitors (TKIs), exhibited the longest median survival following recurrence (37.4 months) in the sample. Treatment, particularly EGFR TKIs for recurrent NSCLC, was observed to significantly prolong survival. The results of the study highlight that various treatment modalities according to the clinical background of the patient should be considered in patients with postoperative recurrent NSCLC.

Prognostic significance of the combined score of endothelial expression of nucleolin and CD31 in surgically resected non-small cell lung cancer

Nucleolin is implicated to play a role in angiogenesis, a vital process in tumor growth and metastasis. However, the presence and clinical relevance of nucleolin in human non small cell lung cancer (NSCLC) remains largely unknown. In this study, we explored the expression and prognostic implication of nucleolin in surgically resected NSCLC patients. A cohort of 146 NSCLC patients who underwent surgical resection was selected for tissue microarray. In this tissue microarray, nucleolin expression was measured by immunofluorescence. Staining for CD31, a marker of endothelial cells, was performed to mark blood vessels. A Cox proportional hazards model was used to assess the prognostic significance of nucleolin. Nucleolin expression was observed in 34.2% of all patients, and 64.1% in high CD31 expression patients. The disease-free survival (DFS) was significantly shorter in patients with high nucleolin (CD31(hi)NCL(hi)) compared to patients with low tumor blood vessels (CD31(lo)NCL(lo)) (5 ys of DFS 24% vs 64%, p = 0.002). Such a difference was demonstrated in the following stratified analyses: stage I (p<0.001), squamous cell carcinoma and adenosquamous cell carcinoma (p = 0.028), small tumor (<5 cm, p = 0.008), and surgery alone (p = 0.015). Multivariate analysis further revealed that nucleolin expression independently predicted for worse survival (p = 0.003). This study demonstrates that nucleolin is associated with the clinical outcomes in postoperative NSCLC patients. Thus, the expression levels of nucleolin may provide a new prognostic marker to identify patients at higher risk for treatment failure, especially in some subgroups.

Concomitant tumor resistance

Concomitant tumor resistance (CR) is a phenomenon in which a tumor-bearing host is resistant to the growth of secondary tumor implants. This phenomenon has been described in human and animal systems and it can be generated by both immunogenic and non-immunogenic tumors. The relevance of CR to the mechanisms of metastases control has been highlighted by numerous observations showing that the removal of human and murine tumors may be followed by an abrupt increase in metastatic growth, suggesting that a primary tumor may exert a controlling action on its metastases which could be considered as secondary tumor implants developed spontaneously during the primary tumor growth. A more profound understanding of the different mechanisms claimed to be associated with the phenomenon of CR could contribute to develop new and more harmless means to manage malignant diseases, especially by limiting the development of metastases that arise after resection of primary tumors or after other stressors that may promote the escape of metastases from dormancy.

Concomitant tumor resistance: the role of tyrosine isomers in the mechanisms of metastases control

Concomitant tumor resistance (CR) is a phenomenon in which a tumor-bearing host is resistant to the growth of secondary tumor implants and metastasis. Although previous studies indicated that T-cell-dependent processes mediate CR in hosts bearing immunogenic small tumors, manifestations of CR induced by immunogenic and nonimmunogenic large tumors have been associated with an elusive serum factor. In a recently published study, we identified this factor as meta-tyrosine and ortho-tyrosine, 2 isomers of tyrosine that would not be present in normal proteins. In 3 different murine models of cancer that generate CR, both meta- and ortho-tyrosine inhibited tumor growth. Additionally, we showed that both isoforms of tyrosine blocked metastasis in a fourth model that does not generate CR but is sensitive to CR induced by other tumors. Mechanistic studies showed that the antitumor effects of the tyrosine isomers were mediated in part by early inhibition of the MAP/ERK pathway and inactivation of STAT3, potentially driving tumor cells into a state of dormancy in G(0)-phase. Other mechanisms, putatively involving the activation of an intra-S-phase checkpoint, would also inhibit tumor proliferation by accumulating cells in S-phase. By revealing a molecular basis for the classical phenomenon of CR, our findings may stimulate new generalized approaches to limit the development of metastases that arise after resection of primary tumors or after other stressors that may promote the escape of metastases from dormancy, an issue that is of pivotal importance to oncologists and their patients.

Effects of Surgery and Chemotherapy on Metastatic Progression of Prostate Cancer: Evidence from the Natural History of the Disease Reconstructed through Mathematical Modeling

This article brings mathematical modeling to bear on the reconstruction of the natural history of prostate cancer and assessment of the effects of treatment on metastatic progression. We present a comprehensive, entirely mechanistic mathematical model of cancer progression accounting for primary tumor latency, shedding of metastases, their dormancy and growth at secondary sites. Parameters of the model were estimated from the following data collected from 12 prostate cancer patients: (1) age and volume of the primary tumor at presentation; and (2) volumes of detectable bone metastases surveyed at a later time. This allowed us to estimate, for each patient, the age at cancer onset and inception of the first metastasis, the expected metastasis latency time and the rates of growth of the primary tumor and metastases before and after the start of treatment. We found that for all patients: (1) inception of the first metastasis occurred when the primary tumor was undetectable; (2) inception of all or most of the surveyed metastases occurred before the start of treatment; (3) the rate of metastasis shedding is essentially constant in time regardless of the size of the primary tumor and so it is only marginally affected by treatment; and most importantly, (4) surgery, chemotherapy and possibly radiation bring about a dramatic increase (by dozens or hundred times for most patients) in the average rate of growth of metastases. Our analysis supports the notion of metastasis dormancy and the existence of prostate cancer stem cells. The model is applicable to all metastatic solid cancers, and our conclusions agree well with the results of a similar analysis based on a simpler model applied to a case of metastatic breast cancer.

Prognostic impact of local treatment against postoperative oligometastases in non-small cell lung cancer

OBJECTIVES

In this study, we investigated prognostic factors associated with survival after distantly metastatic recurrence in surgically resected non-small cell lung cancer (NSCLC), and clarified the influence of local treatment on the prognosis for oligometastatic recurrence.

METHODS

From 1994 through 2004, 418 consecutive patients with NSCLC underwent complete resection; 138 experienced a postoperative recurrence by December 2005. Of those, we reviewed 93 patients with only distant metastases for clinicopathological information, treatment modality, and survival.

RESULTS

For the 93 patients with distant metastasis alone, the 2- and 5-year survival rates after recurrence were 43.9% and 38.7%, respectively. Of those patients, 44 first received local treatment, including radiotherapy in 31 and a surgical resection in 13. Their recurrent disease (oligometastases) was limited with the potential to be controlled with local treatment. The targeted metastatic organs were brain in 14 patients, bone in 14, lungs in 12, and other organs in 4. Significant prognostic factors for postrecurrence survival included adenocarcinoma histology, long disease-free interval (DFI) (1 year or longer), and the performance of local treatment for oligometastases.

CONCLUSION

Local therapy such as radiotherapy and surgery, might be considered first-line treatment in patients with postoperative oligometastatic recurrence, especially those with a DFI ≥ 1 year.

The effects of surgery on tumor growth: a century of investigations

A few clinical investigations suggest that while primary breast cancer surgical removal favorably modifies the natural history for some patients, it may also hasten the metastatic development for others. The concepts underlying this disease paradigm, i.e. tumor homeostasis, tumor dormancy and surgery-driven enhancement of metastasis development, have a long history that is reviewed. The review reveals the context in which these concepts were conceived and structured to explain experimental data and shows that they are not so new and far fetched. The idea that surgical cancer resection has both beneficial and adverse effects upon cancer spread and growth that result from the modulation of tumor dormancy by the resection should be considered a potentially fruitful working hypothesis.

The immunomodulatory effects of laparoscopic surgery

Laparoscopic alternatives to conventional surgical procedures confer many advantages to patients including reduced postoperative pain, shortened convalescence and, perhaps, improved disease-related outcomes. The diminished degree of immune dysfunction apparent with these techniques may underpin these beneficial aspects. However, minimal access is accompanied by various ancillary anesthetic and mechanical associations (including the induction of a carbon dioxide pneumoperitoneum), which must be considered in addition to reduced tissue trauma when attempting to correlate cause with effect. Furthermore, the opportunity to establish causation between the immunomodulatory aspects of laparoscopy and subsequent clinical outcome by prospective, randomized study is difficult because of the rapid incorporation of minimal access techniques into clinical practice. Therefore, experimental in vitro and in vivo studies must be used to complement the limitations of clinical studies in this area. Although the initial investigations into the immunological effects of laparoscopy are encouraging, many of the intricacies associated with this approach still await elaboration.

Inhibition of urokinase plasminogen activator with a novel enzyme inhibitor, WXC-340, ameliorates endotoxin and surgery-accelerated growth of murine metastases

The urokinase plasminogen activator (u-PA) is intimately associated with tumour invasion and metastases. Surgery facilitates accelerated metastatic tumour growth in murine models, a phenomenon related to elevated perioperative bacterial lipopolysaccaride (LPS) and inflammatory cytokine levels. The objectives of the study were to examine the role of u-PA in cytokine-enhanced tumour cell invasion in vitro and surgery-induced accelerated metastatic tumour growth in vivo and to assess the potential benefit of a novel selective u-PA inhibitor WXC-340 in this setting. CT-26 murine colorectal carcinoma cells were stimulated with LPS, tumour necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6). Cell supernatant u-PA expression and activity were determined using a colorimetric assay and Western blot analysis, respectively. Baseline and cytokine-stimulated in vitro invasion were assessed using ECmatrix invasion chambers. Two established murine models of accelerated metastatic tumour growth were used to investigate the consequences of u-PA inhibition on postoperative metastatic tumour burden. The effect of u-PA inhibition in vitro and in vivo was examined using the novel selective u-PA inhibitor, WXC-340. Proinflammatory cytokine stimulation significantly enhanced in vitro u-PA expression, activity and extracellular matrix invasion by approximately 50% compared to controls (P<0.05). This was abrogated by WXC-340. In vivo WXC-340 almost completely ameliorated both LPS- and surgery-induced, metastatic tumour growth compared to controls (P>0.05). In conclusion, u-PA cascade is actively involved in cytokine-mediated enhanced tumour cell invasion and LPS and surgery-induced metastatic tumour growth. Perioperative u-PA inhibition with WXC-340 may represent a novel therapeutic paradigm.

Can surgery for cancer accelerate the progression of secondary tumors within residual minimal disease at both local and systemic levels?

BACKGROUND

Surgical removal remains the principal treatment modality in the management of lung cancer. Our aim is to characterize the effects of tumor removal on subsequent tumor recurrence at both local and systemic levels.

METHODS

C57/BL6 mice [10/group] underwent a mammary fat pad inoculation of 3LL cells [5 x 10(5)/animal] and were divided into two groups. Group 1 served as control while mice in group 2 were further subdivided into groups 2A and 2B. After 2 weeks, all mice in 2A were killed, and primary tumors and lungs were excised. At 2 weeks, primary tumors were excised completely for all mice in group 2B. These mice were then recovered and recurrent tumor growth evaluated for a further 2 weeks. Four weeks from the onset of the study, all remaining primary tumors and lungs were excised from groups 1 and 2.

RESULTS

After 4 weeks undisturbed growth, primary tumors in group 1 reached a mean size of 2.85 +/- 0.33 cm. After 2 weeks growth, primary tumors in groups 2A and 2B were comparable at 1.36 +/- 0.44 m and 1.53 +/- 0.29 cm, respectively. Two weeks after primary tumor excision, recurrent tumors in group 2B had reached a mean size of 2.65 +/- 0.74 cm. Moreover, for several animals, recurrent tumors rapidly reached similar volumes to that of primary tumors in group 1. Primary tumors were typically encapsulated and nonadherent. In contrast, recurrent tumors were locally invasive and adherent to chest wall and wound. Interestingly, pulmonary metastatic burden was increased in group 2B relative to group 1. Histologic examination revealed increased mitosis in recurrent tumors when compared with primary tumors.

CONCLUSIONS

Tumor removal is followed by accelerated growth of locally recurrent tumors and metastases. Moreover, recurrent tumors are more locally invasive than primary tumors. These findings strongly indicate that resection may be followed by tumor progression in residual disease.

Predicting postrecurrence survival among completely resected nonsmall-cell lung cancer patients

BACKGROUND

Survival after recurrence subsequent to complete resection of nonsmall-cell lung cancer (NSCLC) has been considered a multifactorial process dependent on demographic, clinical, biological, and treatment characteristics. This study sought to quantify the prognostic effects of these characteristics on postrecurrence survival.

METHODS

Three hundred ninety NSCLC patients who underwent complete resection and subsequently had recurrent cancer were studied. The associations between characteristics of both the initial and recurrent disease with postrecurrence survival were evaluated by Cox proportional hazards models. A multivariable Cox model determined those factors most strongly associated with postrecurrence survival . A simple algorithm based on this model facilitates estimating risk of postrecurrence mortality, as quantified by risk score points.

RESULTS

The factors most strongly associated with postrecurrence survival were performance status at recurrence (3 or 4, 4.2 points; 2, 2.8 points; and 1, 1.5 points), symptoms at recurrence (3.6 points), liver recurrence (2.3 points), initial lung cancer stage IIB or worse (1.8 points), and multiple recurrences (1.0 points). Based on these factors, patients were stratified as low risk (4.0 or fewer total points), moderate-low risk (4.1 to 6.1 points), moderate-high risk (6.1 to 8.0 points), and high risk (more than 8.0 points), with 12-month survival of 75%, 51%, 25%, and 9%, respectively. Postrecurrence survival was significantly different across groups (p < 0.01).

CONCLUSIONS

The proposed prediction instrument offers clinicians a succinct tool for rapidly evaluating mortality risk after recurrence. The characteristics comprising this instrument can be easily ascertained and measured, making it of potential clinical value.

Cancer surgery: risks and opportunities

In the recent past, several papers have pointed to the possibility that tumour removal generates a permissive environment in which tumour growth is potentiated. This phenomenon has been coined "perioperative tumour growth" and whilst it represents a departure in terms of our attitude to the surgical process, this concept was first hinted at by Paget(1) himself. Despite this, the time interval immediately before and after cancer surgery (i.e. the perioperative period) remains an underutilised interval during which chemotherapeutic regimens are rarely implemented. Herein, we present a summarised review of the literature that supports the concept that tumour removal may potentiate the growth of residual neoplastic disease. We also outline current knowledge regarding underlying mechanisms and in this manner highlight potential therapeutic entry points. Finally, we emphasise the urgent need for trials of agents that could protect patients against the harmful host-tumour interactions that may occur during the perioperative period.

Surgically induced accelerated local and distant tumor growth is significantly attenuated by selective COX-2 inhibition

BACKGROUND

Even after apparently curative resection, lung cancer recurrence continues to lead to high mortality levels. The aim of this study was to assess the effects of cyclooxygenase-2 (COX-2) inhibitor on local and systemic recurrent tumor growth.

METHODS

C57BL/6 mice underwent mammary fat pad inoculation with 3LL cells. After two weeks growth, flank tumors were resected completely and followed for recurrent tumor growth. Postresection mice were randomized to receive placebo alone (group 1) or the selective COX-2 inhibitor, rofecoxib (group 2), daily for two weeks by tube feeding. Recurrent tumor growth kinetics were compared for both groups. Two weeks following primary tumor excision animals were sacrificed, after which lungs were resected and pulmonary metastatic burden was assessed using the lung-body weight ratio. Apoptotic and mitotic indices were established for recurrent tumors and lungs, using hematoxylin and eosin histology.

RESULTS

Two weeks postexcision of the primary tumor, recurrent tumors in the placebo group were significantly greater than the treatment group (p = 0.002). While primary tumors were typically encapsulated and not adherent, recurrent tumors in the placebo group were invasive, adherent to the chest wall and the overlying wound. In contrast, recurrent tumors in the treatment group were nonadherent to the chest wall. Moreover, postoperative pulmonary metastatic burden was significantly reduced in treated animals. Histologic examination revealed increased apoptosis as well as an increase in the apoptosis-mitosis ratio in treated animals.

CONCLUSIONS

Primary tumor excision was associated with accelerated local and systemic tumor recurrence. However, these effects were significantly attenuated using selective COX-2 inhibition. The COX-2-inhibition was associated with increased levels of apoptosis. These findings endorse a role for COX-2 inhibition in the secondary prevention of lung cancer recurrence at both local and systemic levels.

Mutations of the epidermal growth factor receptor gene predict prolonged survival after gefitinib treatment in patients with non-small-cell lung cancer with postoperative recurrence

PURPOSE

To evaluate the relationship between mutations of the epidermal growth factor receptor (EGFR) gene and the effectiveness of gefitinib treatment in patients with recurrent lung cancer after pulmonary resection.

PATIENTS AND METHODS

We sequenced exons 18-21 of the EGFR gene using total RNA extracted from 59 patients with lung cancer who were treated with gefitinib for recurrent lung cancer. Gefitinib effectiveness was evaluated by both imaging studies and change in serum carcinoembryonic antigen (CEA) levels.

RESULTS

EGFR mutations were found in 33 patients (56%). Of these mutations, 17 were deletions around codons 746-750 and 15 were point mutations (12 at codon 858, three at other codons), and one was an insertion. EGFR mutations were significantly more prevalent in females, adenocarcinoma, and never-smokers. Gefitinib treatment resulted in tumor shrinkage and/or CEA decrease to less than half of the baseline level in 26 patients, tumor growth and/or CEA elevation in 24 patients, and gefitinib effect was not assessable in nine patients. Female, never-smoking patients with adenocarcinoma tended to respond better to gefitinib treatment. Gefitinib was effective in 24 of 29 patients with EGFR mutations, compared with two of 21 patients without mutations (P < .0001). Of note, del746-750 might be superior to L858R mutations for prediction of gefitinib response. Patients with EGFR mutations survived for a longer period than those without the mutations after initiation of gefitinib treatment (P = .0053).

CONCLUSION

EGFR mutations were a good predictor of clinical benefit of gefitinib in this setting.

Excisional surgery for cancer cure: therapy at a cost

Excisional surgery is one of the primary treatment modalities for cancer. Minimal residual disease (MRD) is the occult neoplastic disease that remains in situ after curative surgery. There is increasing evidence that tumour removal alters the growth of MRD, leading to perioperative tumour growth. Because neoplasia is a systemic disease, this phenomenon may be relevant to all patients undergoing surgery for cancer. In this review we discuss the published work that addresses the effects of tumour removal on subsequent tumour growth and the mechanisms by which tumour excision may alter residual tumour growth. In addition, we describe therapeutic approaches that may protect patients against any oncologically adverse effects of tumour removal. On the basis of the evidence presented, we propose a novel therapeutic paradigm; that the postoperative period represents a window of opportunity during which the patient may be further protected against the oncological effects of tumour removal.

Hematogenous dissemination of lung cancer cells during surgery: quantitative detection by flow cytometry and prognostic significance

Shedding of neoplastic cells into the circulation is an essential event for the hematogenous metastasis of solid tumors. Recently, several studies reported that a high frequency of cancer cells could be detected in the bloodstream during surgery. The intraoperative detection of hematogenous dissemination of cancer cells was able to identify a subset of patients with malignant diseases at high risk for postoperative metastasis and to predict a poor prognosis. In order to evaluate the association between intraoperative dissemination of cancer cells and postsurgical survival of patients with non-small cell lung cancer (NSCLC), we developed a flow cytometric assay for specific detection of lung cancer cells in the blood. The monocyte-enriched population in the blood was separated by a modified Ficoll-Hypaque density centrifugation and then labeled with a combination of monoclonal antibodies specific for CD45, cytokeratin (CK) and two antigens expressed on lung cancer cells (2F7 and S5A). The assay could detect quantitatively lung cancer cells (defined as CD45(-1) CK(+) 2F7/S5A(+) cells), with the sensitivity limit of one cancer cell in 10(5) normal leukocytes. The specificity for lung cancer was 97%, which was calculated from the results of healthy subjects (20 cases) and patients affected with benign pulmonary diseases (26 cases) or esophageal cancer (14 cases). Blood samples of 31 NSCLC patients were collected from pulmonary vein during open thoracic surgery. Fifteen of them (48.4%) were found to have positive test results. The average cancer cell counts in these cases were 0.306 x 10(6)/l. Patients under 55 years of age had a significantly higher percentage of positive findings than those over 55 years of age (P < 0.05). The positive rate increased over the stages and lymph node status, but the differences were not statistically significant. Moreover, patients with squamous cell carcinoma at later stages (stages III and IV) had an increased frequency of positive test results than those at earlier stages (stages I and II, P < 0.05). In contrast, no such a difference was found in cases with adenocarcinoma. On the basis of 30-months follow-up date, the median survival time and 2-year survival rate for patients with positive and negative findings were 11 vs. 27 months, and 26.7 vs. 62.5%, respectively. There was a statistically significant difference between overall survival curves that favored the patients with negative test results (P = 0.023). Multivariate analysis indicated the stage of disease and the positive test results as two independent factors that affected survival time (P = 0.017 and 0.027). When a comparison was made within the patients at stages III and IV, the presence of cancer cells in blood was associated with a significantly shorter survival. These data indicate that the hematogenous dissemination of lung cancer cells during surgery would be one of the mechanisms of postoperative tumor metastasis. The detection of these cells may help to identify patients with poor prognosis.

Micrometastasis in the bone marrow of patients with lung cancer associated with a reduced expression of E-cadherin and beta-catenin: risk assessment by immunohistochemistry

BACKGROUND

The presence of disseminated tumor cells in bone marrow is considered to be a premetastatic state, which is called micrometastasis. To evaluate the relationship between micrometastasis and cellular adhesion molecules in the primary lesion, E-cadherin and beta-catenin were immunohistochemically investigated. Methods. Fifty-eight patients with non-small cell lung cancer who underwent a complete resection were entered into this study. Tumor cells in bone marrow aspirates were detected by immunohistochemistry using cytokeratin (CK) 18. Immunohistochemical studies of E-cadherin and beta-catenin were performed in the corresponding primary tumor.

RESULTS

CK-positive cells were detected in the bone marrow aspirates from 27 of 58 patients. A reduced expression of the E-cadherin and beta-catenin was found in 16 (27.6%) and in 22 (37.9%) of 58 patients, respectively. In 26 cases with a reduced expression of E-cadherin and/or beta-catenin, 16 cases had CK-positive cells, whereas 11 of 32 cases with normal expression of both factors had CK-positive cells (P=.0392). The patients with micrometastasis demonstrated an earlier recurrence (P =.0642) and a significantly poorer survival (P =.0437) than those without such cells.

CONCLUSIONS

Micrometastasis in the bone marrow might be a significant predictor of poor prognosis, and a reduced expression of E-cadherin and beta-catenin are important determinants for the metastatic capability of individual cancer cells.

Unfavorable prognosis of patients with non-small cell lung carcinoma associated with HLA-A2

BACKGROUND

HLA class I molecules present antigenic peptides to cytotoxic T lymphocytes and, thus, play an important role in immune surveillance. Since 1970s there have been many reports of an increased frequency of one or more HLA haplotype in association with autoimmune disease, and malignancy. We studied types of HLA class I antigens in 204 resected non-small cell lung carcinoma (NSCLC) patients and also examined its correlation with clinicopathologic features and prognosis.

METHOD

Serological typing for HLA class I antigens was performed using a microcytotoxicity test. The disease-free survival curves were calculated by the Kaplan-Meier method and then compared using the Logrank test. Multivariate analysis was carried out by Cox's proportional hazard method.

RESULTS

The difference in disease-free survival time between the HLA-A2 present group and A2 absent group was significant (P = 0.040). The 3-year disease-free survival rate of all patients was 44% in HLA-A2 present group and 66% in A2 absent group. When a comparison was made within the group with stage I, expression of HLA-A2 was the only independent factor that affected survival time by multivariate analysis (P = 0.0457).

CONCLUSIONS

Expression of HLA-A2 was considered as one of the unfavorable prognostic factors in NSCLC patients. Our results suggested expression of HLA-A2 in NSCLC patients was one of the mechanisms of escape from immune surveillance.

Rib metastasis appearing 8 years after surgery for lung cancer: report of a case

A 39-year-old man underwent a right upper lobectomy and lymph node dissection for right lung adenocarcinoma on March 7, 1988. He was referred for an evaluation of a systemic bone scintillation scan on October 29, 1996. A hot spot at the right fourth rib was recognized. After performing needle aspiration cytology, a diagnosis of adenocarcinoma was made. This case was considered to be rib metastasis occurring 8 years after surgery for lung cancer. In general, regular follow-up examinations are performed for at least 5 years after surgery; however, surgeons should also keep such late metastatic cases in mind.

Mutations of the P53 tumor suppressor gene as clonal marker for multiple primary lung cancers

OBJECTIVES

Second primary lung cancers are prevalent after treatment for initial lung cancer, and the lung is also one of the most frequent sites for recurrence after removal of early-stage lung cancer. The objective of the present study is to clarify the clonal origin of the second tumor with the p53 gene mutation used as a clonal marker.

METHODS

Of 794 consecutive patients who underwent pulmonary resection for primary lung cancer from 1980 to 1993, 22 required second pulmonary resection during the follow-up period, with a median interval of 38 months. We examined 16 of these patients for mutations of the p53 gene occurring in exons 5 through 8 by the polymerase chain reaction/single strand conformation polymorphism method. Differential diagnosis was also made on a morphologic basis, considering the degree of cellular differentiation and cytologic subtypes.

RESULTS

Nine of the 16 patients analyzed had at least one p53 mutation in their tumors. We were thus able to make molecular diagnoses for these patients. The mutational status of the p53 gene was discordant in all nine patients, suggesting a different clonal origin despite the fact that six of them had almost identical histologic features.

CONCLUSIONS

Analysis of p53 gene mutations was thus useful in distinguishing second primary lung cancers from recurrent tumors. The observed heterogeneity of p53 status was also in line with the "field cancerization" concept.