Patients with colorectal cancer and brain metastasis: The relevance of extracranial metastatic patterns predicting time intervals to first occurrence of intracranial metastasis and survival.

The aim of the study was to investigate the predictive impact of extracranial metastatic patterns on course of disease and survival in patients with colorectal cancer (CRC) and brain metastasis (BM). A total of 228 patients (134 male [59%], 94 female [41%]) with histologically proven CRC and BM were classified into different groups according to extracranial metastatic patterns. Time intervals to metastatic events and survival times from initial CRC diagnosis, extracranial and intracranial metastasis were analyzed. Extracranial organs mostly affected were liver (102 of 228 [44.7%]) and lung (96 of 228 [42.1%]). Liver and lung metastases were detected in 31 patients (13.6%). Calculated over the entire course of disease, patients with lung metastasis showed longer overall survival (OS) than patients with liver metastasis or patients without lung metastasis (43.9 vs 34.6 [P = .002] vs 35.0 months [P = .002]). From the date of initial CRC diagnosis, lung metastasis occurred later in CRC history than liver metastasis (24.3 vs 7.5 months). Once lung metastasis was diagnosed, BM occurred faster than in patients with liver metastasis (15.8 vs 26.0 months; Δ 10.2 months). Accordingly, OS from the diagnosis of liver metastasis was longer than from lung metastasis (27.1 vs 19.6 months [P = .08]). Once BM was present, patients with lung metastasis lived longer than patients with liver metastasis (3.8 vs 1.1 months [P = .028]). Shortest survival times in all survival categories analyzed revealed patients with concurrent liver and lung metastasis. Patients with CRC and BM form a heterogeneous cohort where extracranial metastasis to liver or lungs predicts survival.

Brain Metastasis in Colorectal Cancer Patients: Survival and Analysis of Prognostic Factors.

BACKGROUND: The purpose of the study was to characterize the rare cohort of patients (pts) with metastatic colorectal cancer (mCRC) and brain metastasis (BM) and to identify prognostic subgroups. PATIENTS AND METHODS: In collaboration with the Munich Cancer Registry, pts with mCRC and BM who were diagnosed between 1998 and 2011 were identified. Survival from the time of first diagnosis of colorectal cancer (CRC) (OS-1), from the time of diagnosis of metastatic disease (OS-2) and of BM (OS-3) was calculated regarding (1) the temporal occurrence of extra- and intracranial metastasis (meta- vs. synchronous) and (2) tumor and patient characteristics. For survival analysis the Kaplan-Meier estimator and Cox regression models were used. RESULTS: A total of 228 pts (134 male [59%], 94 female [41%]) were identified. The median age was 63 years (142 pts [62%] were 65 years of age or younger). Most pts presented with primary tumors staged T3/4, N+, Grade 2. The primary tumor was located predominantly in the left colon (155 pts; 68%), especially in the rectum (95 pts; 42%). Median OS-1 was 35.6 months (95% confidence interval [CI], 30.1-41.1 months), OS-2 was 16.5 months (95% CI, 13.9-19.1 months), and OS-3 was 2.0 months (95% CI, 1.5-2.5 months). Median time from first CRC diagnosis to BM was 29.2 months. Subsequent BM after extracranial metastasis were observed in 184 pts (80.7%), whereas 31 pts (13.6%) presented with solitary BM. Univariate analysis did not reveal a prognostic variable for overall survival after diagnosis of BM. CONCLUSION: This study presents the largest number of pts with mCRC and BM analyzed to date. The results show that most mCRC pts develop BM as a late step in the course of disease. Median time from first CRC diagnosis to BM is 29.2 months. Only a few pts were diagnosed with BM early in the disease or with solitary BM. When BM is present survival is poor.

Liver transplantation for unresectable hepatocellular carcinoma in normal livers.

BACKGROUND & AIMS: The role of liver transplantation in the treatment of hepatocellular carcinoma in livers without fibrosis/cirrhosis (NC-HCC) is unclear. We aimed to determine selection criteria for liver transplantation in patients with NC-HCC. METHODS: Using the European Liver Transplant Registry, we identified 105 patients who underwent liver transplantation for unresectable NC-HCC. Detailed information about patient, tumor characteristics, and survival was obtained from the transplant centers. Variables associated with survival were identified using univariate and multivariate statistical analyses. RESULTS: Liver transplantation was primary treatment in 62 patients and rescue therapy for intrahepatic recurrences after liver resection in 43. Median number of tumors was 3 (range 1-7) and median tumor size 8 cm (range 0.5-30). One- and 5-year overall and tumor-free survival rates were 84% and 49% and 76% and 43%, respectively. Macrovascular invasion (HR 2.55, 95% CI 1.34 to 4.86), lymph node involvement (HR 2.60, 95% CI 1.28 to 5.28), and time interval between liver resection and transplantation < 12 months (HR 2.12, 95% CI 0.96 to 4.67) were independently associated with survival. Five-year survival in patients without macrovascular invasion or lymph node involvement was 59% (95% CI 47-70%). Tumor size was not associated with survival. CONCLUSIONS: This is the largest reported series of patients transplanted for NC-HCC. Selection of patients without macrovascular invasion or lymph node involvement, or patients ≥ 12months after previous liver resection, can result in 5-year survival rates of 59%. In contrast to HCC in cirrhosis, tumor size is not a predictor of post-transplant survival in NC-HCC.

Evaluation of a new prognostic score (Munich score) to predict long-term survival after resection of pulmonary renal cell carcinoma metastases.

BACKGROUND: The aim of this single-center study was to analyze factors predicting long-term outcomes following surgical resection of pulmonary metastases in patients with renal cell carcinoma. METHODS: Two hundred two consecutive patients entered the study. Overall survival was analyzed by the Kaplan-Meier method. Multivariate analysis was performed using Cox regression models. RESULTS: In 175 cases (87%), curative resection of the pulmonary metastases was achievable, with median survival of 43 months. Multivariate analysis revealed complete metastasectomy (R0), metastasis size >3 cm, positive nodal status of the primary tumor, synchronous metastases, pleural infiltration, and tumor-infiltrated hilar or mediastinal lymph nodes as independent prognostic factors for survival. On the basis of these findings, a new scoring system (the Munich score) was established to predict survival, which discriminates 3 groups with low, intermediate, and high risk for poor outcomes (median survival, 90, 31, and 14 months, respectively, P < .001). CONCLUSIONS: The aim of the Munich score is to define patients with low, intermediate, and high risk for poor survival and will help identify patients who may benefit from further adjuvant therapy.

Tumor infiltrated hilar and mediastinal lymph nodes are an independent prognostic factor for decreased survival after pulmonary metastasectomy in patients with renal cell carcinoma.

PURPOSE: Surgical resection remains the most effective treatment in patients with pulmonary metastasis of renal cell carcinoma. To our knowledge the prognostic significance of mediastinal and hilar lymph node metastasis during pulmonary metastasectomy in patients with renal cell carcinoma is unknown. We analyzed the value of computerized tomography to predict mediastinal/hilar lymph node involvement as well as the impact of systematic lymphadenectomy on survival in patients with pulmonary renal cell carcinoma metastasis. MATERIALS AND METHODS: We analyzed survival in 110 patients who underwent resection of pulmonary metastasis of renal cell carcinoma using the Kaplan-Meier method. Multivariate analysis was done by Cox regression analysis. RESULTS: Lymph node metastasis was histologically proved in 35% of patients. Metastasis was not associated with initial tumor grade, lymph node status, the number of pulmonary metastases or recurrent pulmonary metastasis. Computerized tomography had 84% sensitivity and 97% specificity to predict lymph node metastasis. Sensitivity was markedly better for detecting mediastinal than hilar lymph node metastasis (90% vs 69%). Patients with lymph node metastasis had significantly shorter median survival than patients without lymph node metastasis (19 vs 102 months, p <0.001). Multivariate analysis revealed that tumor infiltrated mediastinal lymph nodes were an independent prognostic factor for patient survival. Match paired analysis showed that after lymph node dissection patients showed a trend toward improved survival. CONCLUSIONS: Mediastinal and hilar lymph node metastases significantly correlate with decreased survival. Systematic lymphadenectomy provides valuable information on staging and prognosis in patients with pulmonary metastasis of renal cell carcinoma, and may prolong survival.

Late reuse of liver allografts from brain-dead graft recipients: the Munich experience and a review of the literature.

The increasing donor organ shortage requires the consideration of any possible organ donor in order to meet the current demand. However, the growing number of long-term survivors of liver transplantation may create a situation in which former organ recipients may experience brain death with a functioning graft and therefore become organ donors themselves. Previous reports concerning this rare situation predominantly refer to the reuse of donor organs within the first 8 days after primary liver transplantation. So far, only a single case of late reuse of a donor liver has been published, with 2 additional cases mentioned in a summary of the United Network for Organ Sharing database. Here we report the case of a 43-year-old female donor who had received a liver graft for complications of Budd-Chiari syndrome 5 years before becoming an organ donor herself after cerebral infarction with consecutive brain death.

National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for use of tumor markers in liver, bladder, cervical, and gastric cancers.

BACKGROUND: Updated National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed. METHODS: Published reports relevant to use of tumor markers for 4 cancer sites--liver, bladder, cervical, and gastric--were critically reviewed. RESULTS: Alpha-fetoprotein (AFP) may be used in conjunction with abdominal ultrasound for early detection of hepatocellular carcinoma (HCC) in patients with chronic hepatitis or cirrhosis associated with hepatitis B or C virus infection. AFP concentrations >200 microg/L in cirrhotic patients with typical hypervascular lesions >2 cm in size are consistent with HCC. After a diagnosis of HCC, posttreatment monitoring with AFP is recommended as an adjunct to imaging, especially in the absence of measurable disease. Although several urine markers have been proposed for bladder cancer, none at present can replace routine cystoscopy and cytology in the management of patients with this malignancy. Some may, however, be used as complementary adjuncts to direct more effective use of clinical procedures. Although carcinoembryonic antigen and CA 19-9 have been proposed for use gastric cancer and squamous cell carcinoma antigen for use in cervical cancer, none of these markers can currently be recommended for routine clinical use. CONCLUSIONS: Implementation of these recommendations should encourage optimal use of tumor markers for patients with liver, bladder, cervical, or gastric cancers.

Esophageal leiomyomatosis combined with intrathoracic stomach and gastric volvulus.

CASE REPORT: A 42-year-old female presented with long-standing symptoms suggestive of gastroesophageal reflux disease improved after proton pump inhibitor treatment. An upper endoscopy revealed an intrathoracic position of the stomach (type 4 hiatal hernia) with no mucosal abnormality. Barium swallow demonstrated gastric herniation with gastric volvulus without stenosis. A computed tomographic scan confirmed the intrathoracic location of the stomach associated with thickening and edema of the gastric wall due to gastric volvulus, but no evidence of malignancy. The patient was scheduled for laparoscopic gastric repositioning with anterior hemifundoplication. Due to the incidental intraoperative finding of a large distal esophageal tumor (frozen section: esophageal leiomyomatosis), the operation was converted to conventional distal esophagectomy and proximal gastrectomy with reconstruction using a Merendino procedure. Final histology revealed extensive circumferential leiomyomatosis of the distal esophagus with a diameter of 10 cm. Esophageal leiomyomatosis is an extremely rare pathological finding with <100 cases reported in the literature. CONCLUSION: Any surgeon performing laparoscopic fundoplication has to be ready to deal with such unexpected findings, ie, converting the procedure and doing reconstruction with minimal morbidity. The Merendino procedure is a well-established reconstructive surgical option in cases of tumor formation at the gastroesophageal region with fewer postoperative morbidities like reflux symptoms.

Recipient treatment with L-arginine attenuates donor lung injury associated with hemorrhagic shock.

BACKGROUND: Organ donors are frequently trauma victims, but the impact of donor hemorrhagic shock and resuscitation (HSR) on pulmonary graft function has not been assessed. L-arginine treatment during reperfusion increases the production of endothelial nitric oxide and thus ameliorates ischemia-reperfusion injury. Objective of the present porcine study was to investigate the effect of donor hemorrhage on pulmonary graft function and potential beneficial effects of L-arginine administration. METHODS: In the control-group (n=6), lungs were harvested from donors without hypotensive periods. In the HSR-group (n=6) and HSR-Arg-group (n=6), donors were subjected to hemorrhagic shock (40% blood shed) and resuscitation before harvest. Left lungs were transplanted after hypothermic preservation of 18 hr, and graft function was observed for 6 hr after reperfusion. Recipients in the HSR-Arg-group received a bolus of L-arginine (50 mg/kg BW) intravenously 5 min before reperfusion followed by a continuous intravenous administration of L-arginine 200 mg/kg BW for 2 hr. Tissue specimens and bronchoalveolar lavage fluid were obtained at the end of the observation period. RESULTS: Donor lung function did not differ between study groups. Compared with the control group, pulmonary graft gas exchange was significantly impaired in the HSR-group. Graft function in the HSR-Arg-group did not differ from control organs. Neutrophil fraction, protein content, and malondialdehyde levels in the bronchoalveolar lavage fluid in the HSR-group were higher compared with control and HSR-Arg-Group. CONCLUSION: Although fulfilling ideal donor criteria, pulmonary graft function of lungs harvested from donors subjected to HSR is impaired, but improves significantly when l-arginine is administered during reperfusion.

Does surgical resection of pulmonary metastases of head and neck cancer improve survival?

BACKGROUND: The prognosis of patients with metastasized head and neck cancer is poor. Limited experience exists with the benefit of resection of lung metastases and systematic mediastinal and hilar lymph node dissection on survival of patients with head and neck carcinoma. METHODS: Eighty patients undergoing metastasectomy for pulmonary metastases of primary head and neck cancer entered the study. Multivariate analysis was performed by Cox regression analysis. Survival differences between patients operated and those not operated on were analyzed by matched pair analysis. RESULTS: From 1984 until 2006, pulmonary metastases were diagnosed in 332 patients treated for head and neck cancer; 80 of these were admitted to our department for resection. Metastases of the primary head and neck tumor were confirmed histologically in 67 patients. The median overall survival after resection of lung metastases was 19.4 months and was statistically significantly better compared with patients who were not operated on (P < .001). The multivariate analysis after metastasectomy revealed that incomplete resection of pulmonary lesions, complications associated with surgery, and adjuvant therapy of the primary tumor are independent negative prognostic factors for survival. We observed a trend to improved survival in patients without hilar or mediastinal lymph node metastases. CONCLUSION: The survival rate of patients operated on was statistically significantly higher than that of patients with conservative treatment. Even patients with multiple or bilateral pulmonary lesions after curative treatment of a primary tumor should be operated on if there is no contraindication against an extended surgical procedure and a complete resection of the metastases seems achievable.

Comparison of Fenestra VC Contrast-enhanced computed tomography imaging with gadopentetate dimeglumine and ferucarbotran magnetic resonance imaging for the in vivo evaluation of murine liver damage after ischemia and reperfusion.

OBJECTIVES: Comparison of intravenous Fenestra VC-enhanced computed tomography (CT) with gadopentetate dimeglumine and Ferucarbotran contrast-enhanced magnetic resonance imaging (MRI) for the in vivo imaging of hepatic ischemia/reperfusion injury (IRI) in a murine model. MATERIAL AND METHODS: After induction of hepatic IRI by left liver lobe (LLL) ischemia (30, 45, and 75 minutes) and reperfusion (4 hours and 24 hours), a total of 130 mice were imaged either by Fenestra VC-enhanced 3-D CT or by dynamic, T1-weighed gadopentetate dimeglumine or static, T2*-weighed Ferucarbotran 2-D MRI (4.7 T). RESULTS: Detection of liver tissue damage as a consequence of IRI was not possible by CT or MRI without the use of contrast media. (1) Mice subjected to liver IRI (45 minutes of ischemia) and injected with Fenestra VC showed a distinct liver enhancement of the viable liver tissue or a nonenhancement of the necrotic tissue. The Fenestra VC CT-unenhanced liver volume increased as a function of time of ischemia and reperfusion. The unenhanced liver volume also correlated positively with serum liver enzyme activities and damage scores from liver histology. (2) The signal intensities (SI) between normal liver tissue and livers subjected to 30 minutes of ischemia were not different on dynamic gadopentetate dimeglumine-enhanced magnetic resonance images. More severe IRI as induced by 45 or 75 minutes of ischemia was characterized by (a) early hyperenhancement of regions in the LLL with rapid increase of SI higher than that observed in the undamaged liver within the first few minutes and (b) delayed hyperenhancement in the later course after gadopentetate dimeglumine injection, respectively. (3) Ferucarbotran MRI detected signs of IRI after only 30 minutes of liver ischemia and hence detected IRI earlier than Fenestra VC or gadopentetate dimeglumine. With longer duration of ischemia, Ferucarbotran SI increased in the LLL, but viable and necrotic tissues were not clearly distinguishable. CONCLUSIONS: MicroCT with Fenestra VC enhancement and MRI using either gadopentetate dimeglumine or Ferucarbotran enhancement of the liver revealed that all techniques allow in vivo determination of hepatic IRI as a function of the duration of ischemia and reperfusion of the liver. However, Fenestra VC-enhanced CT of the murine liver is superior to gadopentetate dimeglumine and Ferucarbotran for localization, quantification, and differentiation of viable from metabolically inactive/damaged liver tissue after hepatic ischemia/reperfusion but Fenestra VC is less sensitive than Ferucarbotran to detect the early onset of subtle consequences of hepatic IRI.

Therapeutic T cells induce tumor-directed chemotaxis of innate immune cells through tumor-specific secretion of chemokines and stimulation of B16BL6 melanoma to secrete chemokines.

BACKGROUND: The mechanisms by which tumor-specific T cells induce regression of established metastases are not fully characterized. In using the poorly immunogenic B16BL6-D5 (D5) melanoma model we reported that T cell-mediated tumor regression can occur independently of perforin, IFN-gamma or the combination of both. Characterization of regressing pulmonary metastases identified macrophages as a major component of the cells infiltrating the tumor after adoptive transfer of effector T cells. This led us to hypothesize that macrophages played a central role in tumor regression following T-cell transfer. Here, we sought to determine the factors responsible for the infiltration of macrophages at the tumor site. METHODS: These studies used the poorly immunogenic D5 melanoma model. Tumor-specific effector T cells, generated from tumor vaccine-draining lymph nodes (TVDLN), were used for adoptive immunotherapy and in vitro analysis of chemokine expression. Cellular infiltrates into pulmonary metastases were determined by immunohistochemistry. Chemokine expression by the D5 melanoma following co-culture with T cells, IFN-gamma or TNF-alpha was determined by RT-PCR and ELISA. Functional activity of chemokines was confirmed using a macrophage migration assay. T cell activation of macrophages to release nitric oxide (NO) was determined using GRIES reagent. RESULTS: We observed that tumor-specific T cells with a type 1 cytokine profile also expressed message for and secreted RANTES, MIP-1alpha and MIP-1beta following stimulation with specific tumor. Unexpectedly, D5 melanoma cells cultured with IFN-gamma or TNF-alpha, two type 1 cytokines expressed by therapeutic T cells, secreted Keratinocyte Chemoattractant (KC), MCP-1, IP-10 and RANTES and expressed mRNA for MIG. The chemokines released by T cells and cytokine-stimulated tumor cells were functional and induced migration of the DJ2PM macrophage cell line. Additionally, tumor-specific stimulation of wt or perforin-deficient (PKO) effector T cells induced macrophages to secrete nitric oxide (NO), providing an additional effector mechanism for T cell-mediated tumor regression. CONCLUSION: These data suggest two possible sources for chemokine secretion that stimulates macrophage recruitment to the site of tumor metastases. Both appear to be initiated by T cell recognition of specific antigen, but one is dependent on the tumor cells to produce the chemokines that recruit macrophages.

Multifocal manifestation does not affect vascular invasion of hepatocellular carcinoma: implications for patient selection in liver transplantation.

BACKGROUND AND AIMS: Liver transplantation (OLT) for hepatocellular carcinoma (HCC) improves patient survival when tumor size and number are limited according to the Milan criteria. However, the impact of tumor size vs. the number of lesions for tumor recurrence after OLT is unclear. Microvascular invasion appears to be a significant risk factor for tumor recurrence. Therefore, it was the aim of this study to investigate tumor differentiation and microvascular invasion in relation to tumor number and size and their impact on survival after transplantation. PATIENTS AND METHODS: In 97 adult HCC patients who underwent OLT between June 1985 and December 2005 the incidence of microvascular invasion, tumor differentiation, and the number and size of tumor lesions were analyzed retrospectively. Their impact on survival was studied by multivariate analysis. RESULTS: Microvascular invasion was the only independent negative predictor of survival after OLT for HCC (p = 0.025). Tumor size > 5 cm was predictive for microvascular invasion (p = 0.007). In contrast, tumor number did not affect the incidence of microvascular invasion or cumulative survival. CONCLUSION: The size of the largest HCC lesion, but not the number of tumors, determined microvascular invasion, a predictor of the outcome following OLT for HCC. Thus, the number of HCC lesions should not be applied to patient selection prior to OLT. These data support the extension of the Milan criteria for the selection of HCC patients for OLT with regard to tumor number, but not tumor size.

Liver resection or combined chemoembolization and radiofrequency ablation improve survival in patients with hepatocellular carcinoma.

BACKGROUND/AIMS: To evaluate the long-term outcome of surgical and non-surgical local treatments of patients with hepatocellular carcinoma (HCC). METHODS: We stratified a cohort of 278 HCC patients using six independent predictors of survival according to the Vienna survival model for HCC (VISUM-HCC). RESULTS: Prior to therapy, 224 HCC patients presented with VISUM stage 1 (median survival 18 months) while 29 patients were classified as VISUM stage 2 (median survival 4 months) and 25 patients as VISUM stage 3 (median survival 3 months). A highly significant (p < 0.001) improved survival time was observed in VISUM stage 1 patients treated with liver resection (n = 52; median survival 37 months) or chemoembolization (TACE) and subsequent radiofrequency ablation (RFA) (n = 44; median survival 45 months) as compared to patients receiving chemoembolization alone (n = 107; median survival 13 months) or patients treated by tamoxifen only (n = 21; median survival 6 months). Chemoembolization alone significantly (p < or = 0.004) improved survival time in VISUM stage 1-2 patients but not (p = 0.341) in VISUM stage 3 patients in comparison to those treated by tamoxifen. CONCLUSION: Both liver resection or combined chemoembolization and RFA improve markedly the survival of patients with HCC.

Alpha-gluthathione S-transferase as an early marker of hepatic ischemia/reperfusion injury after liver resection.

Organ dysfunction following liver resection is one of the major postoperative complications of liver surgery. The Pringle maneuver is often applied during liver resection to minimize bleeding, which in turn complicates the postoperative course owing to liver ischemia and reperfusion. Routinely, hepatocellular damage is diagnosed by, for example, abnormal aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and the prothrombin time (PT). The cytosolic liver enzyme alpha-glutathione S-transferase (alpha-GST) has recently been shown to have good sensitivity for detecting hepatic injury after acetaminophen poisoning or liver transplantation, but its role in non-transplantation liver surgery has not been assessed. In this prospective randomized clinical study, the diagnostic role of plasma alpha-GST following warm ischemia and reperfusion is reported. A total of 75 patients who underwent liver resection were randomly assigned to three groups: (1) without Pringle (NPR); (2) with Pringle (PR); (3) with ischemic preconditioning by 10 minutes of ischemia and reperfusion each prior to the Pringle manuever (IPC). The major findings are as follows: (1) ALT, AST, and alpha-GST increased upon liver manipulation as early as prior to resection, with a rapid return of alpha-GST values to preoperative levels, whereas ALT and AST further increased on the first postoperative day. (2) In the PR group, alpha-GST, but not ALT and AST, was significantly elevated compared with that in the NPR group at 15 and 30 minutes and 2 hours after resection/reperfusion. In addition, only levels of alpha-GST significantly correlated with the Pringle duration. (3) The ischemia/reperfusion-induced early rise in alpha-GST was completely prevented by ischemic preconditioning. Moreover, only alpha-GST concentrations (> 490 microg L(-1)) determined early after resection (2 hours) predicted postoperative liver dysfunction (24 hours PT < 60%) with a positive predictive value of 74% and a negative predictive value of 76%. Thus alpha-GST seems to be a sensitive, predictive marker of ischemia/reperfusion-induced hepatocellular injury and postoperative liver dysfunction.

Estimation of liver size for liver transplantation: the impact of age and gender.

In general, the liver is considered to be larger in males than in females. In the present study, data on liver weight from 728 legal autopsies were analyzed with respect to gender, age, body height (BH), body weight (BW), body mass index (BMI), and body surface area (BSA). Descriptive statistics revealed that liver weight increases with age, reaching maximum values between 41 and 50 years in men and between 51 and 60 years in women. Thereafter, liver weight decreases again. Because this loss in liver weight starts earlier in men while liver weight continues to rise in women, the difference in liver weight between men and women is lost above the age of 50. Thus, this age defines a threshold value below which gender is expected to be a critical factor in the calculation of liver weight. When demographic data mentioned above were subjected to multiple stepwise linear regression analysis, liver weight (LW) was best predicted in younger people (16-50 years) by body weight, age, and gender: LW (g) = 452 + 16.34 x BW + 11.85 x age - 166 x gender (r(2) = 0.381; "gender": 1 = female, 0 = male). In contrast, in elderly people (51-70 years) LW was best predicted by BW and age only. Gender was not a significant factor. LW (g) = 1390 + 15.94 x BW - 12.86 x age (r(2) = 0.35). When these formulas were applied to demographic data from 97 organ donors and compared to published formulas (which, however, do not consider the age-dependent effects of gender), the new formulas best predicted male to female liver weight ratios in younger and elderly donors. In conclusion, the new formulas might better predict liver weight in organ donors and transplant recipients to avoid liver size mismatch.