The impact of neoadjuvant systemic treatment on postoperative complications in breast cancer surgery.

PURPOSE: The aim of the study was to analyze the impact of neoadjuvant systemic treatment (NST) on postoperative complications and the beginning of adjuvant treatment. METHODS: This study includes data from a prospectively maintained database including patients with breast cancer (BC) stage I-IV with or without NST undergoing breast cancer surgery between January 2010 and September 2021. RESULTS: Out of 517 enrolled patients, 77 received NST, 440 had primary breast surgery. After NST patients underwent surgery after a meantime of 34 days (26.5-40 days). No statistical significance could be found comparing the complication grading according to the Clavien Dindo classification. The complications were most frequently rated as grade 3b. There were no complications with grade 4 or higher. When differentiating into short and long-term, the overall rate of short-term complications was 20.3% with no significant difference between the two groups (20.8% vs. 20.2%). Regarding long-term complications, there was more impairment of shoulder mobility (26.0% vs. 9.5%, p ≤ 0.001) and chronic pain (42.9% vs. 28.6%, p ≤ 0.016) for patients with NST. The beginning of the administration of the adjuvant treatment was comparable in both groups (46.3 days vs. 50.5 days). CONCLUSION: In our cohort, complications between both groups were comparable according to Clavien Dindo. This study shows that NST has no negative impact on postoperative short-term complications and most importantly did not lead to a delay of the beginning of adjuvant treatment. Therefore, NST can be safely admitted, even when followed by extensive breast reconstruction surgery.

The impact of age on patient-reported outcomes after oncoplastic versus conventional breast cancer surgery.

PURPOSE: Some studies have indicated age-specific differences in quality of life (QoL) among breast cancer (BC) patients. The aim of this study was to compare patient-reported outcomes after conventional and oncoplastic breast surgery in two distinct age groups. METHODS: Patients who underwent oncoplastic and conventional breast surgery for stage I-III BC, between 6/2011-3/2019, were identified from a prospectively maintained database. QoL was prospectively evaluated using the Breast-Q questionnaire. Comparisons were made between women < 60 and ≥ 60 years. RESULTS: One hundred thirty-three patients were included. Seventy-three of them were ≥ 60 years old. 15 (20.5%) of them received a round-block technique (RB) / oncoplastic breast-conserving surgeries (OBCS), 10 (13.7%) underwent nipple-sparing mastectomies (NSM) with deep inferior epigastric perforator flap (DIEP) reconstruction, 23 (31.5%) underwent conventional breast-conserving surgeries (CBCS), and 25 (34.2%) received total mastectomy (TM). Sixty patients were younger than 60 years, 15 (25%) thereof received RB/OBCS, 22 (36.7%) NSM/DIEP, 17 (28.3%) CBCS, and 6 (10%) TM. Physical well-being chest and psychosocial well-being scores were significantly higher in older women compared to younger patients (88.05 vs 75.10; p < 0.001 and 90.46 vs 80.71; p = 0.002, respectively). In multivariate linear regression, longer time intervals had a significantly positive effect on the scales Physical Well-being Chest (p = 0.014) and Satisfaction with Breasts (p = 0.004). No significant results were found concerning different types of surgery. CONCLUSION: Our findings indicate that age does have a relevant impact on postoperative QoL. Patient counseling should include age-related considerations, however, age itself cannot be regarded as a contraindication for oncoplastic surgery.

Topotecan plus carboplatin versus standard therapy with paclitaxel plus carboplatin (PC) or gemcitabine plus carboplatin (GC) or pegylated liposomal doxorubicin plus carboplatin (PLDC): a randomized phase III trial of the NOGGO-AGO-Study Group-AGO Austria and GEICO-ENGOT-GCIG intergroup study (HECTOR).

BACKGROUND: Randomized, phase III trial to evaluate safety and efficacy of topotecan and carboplatin (TC) compared with standard platinum-based combinations in platinum-sensitive recurrent ovarian cancer (ROC). PATIENTS AND METHODS: Patients were randomly assigned in a 1:1 ratio to the experimental TC arm (topotecan 0.75 mg/m2/ days 1-3 and carboplatin AUC 5 on day 3 every 3 weeks) or to one of the standard regimes [(PC) paclitaxel plus carboplatin; (GC) gemcitabine plus carboplatin; (PLDC) pegylated liposomal doxorubicin and carboplatin] which could be chosen by individual preference but before randomization. The primary end point was progression-free survival (PFS) after 12 months. Overall survival (OS), response rate, toxicity, quality of life and treatment preference regarding standard treatment were defined as secondary end points. RESULTS: A total of 550 patients were recruited. The PFS rate after 12 months was 37.0% for TC compared with 40.2% in the standard combinations (P = 0.470). The overall response rate was 73.1% for TC versus 75.1% for standard combinations (P = 0.149). After a median follow-up of 20 months, the median PFS was 10 months [95% confidence interval (CI) 9.4-10.6] and did not differ between both arms (P = 0.414). The median OS was 25 months in the TC arm versus 31 months in the standard arm (95% CI: 22.4-27.6 resp. 26.0-36.0; P = 0.163). Severe hematologic toxicities (grade 3/4) were rare in the experimental arm (P < 0.001), with 17.4% leucopenia, 27.8% neutropenia and 15.9% thrombopenia. CONCLUSION: The combination of carboplatin and topotecan was well tolerated with significant lower rates of severe hematological toxicities but did not improve PFS or OS in platinum-sensitive relapsed ovarian cancer compared with established standard regimens.

A prognostic nomogram to predict overall survival in patients with platinum-sensitive recurrent ovarian cancer.

BACKGROUND: Patients with platinum-sensitive recurrent ovarian cancer have variable prognosis and survival. We extend previous work on prediction of progression-free survival by developing a nomogram to predict overall survival (OS) in these patients treated with platinum-based chemotherapy. PATIENTS AND METHODS: The nomogram was developed using data from the CAELYX in Platinum-Sensitive Ovarian Patients (CALYPSO) trial. Multivariate proportional hazards models were generated based on pre-treatment characteristics to develop a nomogram that classifies patient prognosis based on OS outcome. We also developed two simpler models with fewer variables and conducted model validations in independent datasets from AGO-OVAR Study 2.5 and ICON 4. We compare the performance of the nomogram with the simpler models by examining the differences in the C-statistics and net reclassification index (NRI). RESULTS: The nomogram included six significant predictors: interval from last platinum chemotherapy, performance status, size of the largest tumour, CA-125, haemoglobin and the number of organ sites of metastasis (C-statistic 0.67; 95% confidence interval 0.65-0.69). Among the CALPYSO patients, the median OS for good, intermediate and poor prognosis groups was 56.2, 31.0 and 20.8 months, respectively. When CA-125 was not included in the model, the C-statistics were 0.65 (CALYPSO) and 0.64 (AGO-OVAR 2.5). A simpler model (interval from last platinum chemotherapy, performance status and CA-125) produced a significant decrease of the C-statistic (0.63) and NRI (26.4%, P < 0.0001). CONCLUSIONS: This nomogram with six pre-treatment characteristics improves OS prediction in patients with platinum-sensitive ovarian cancer and is superior to models with fewer prognostic factors or platinum chemotherapy free interval alone. With independent validation, this nomogram could potentially be useful for improved stratification of patients in clinical trials and also for counselling patients.

Clinical application of the 21-gene oncotype recurrence score in an older cohort: A single center experience.

BACKGROUND: In early luminal breast cancer, the Oncotype DX® Recurrence Score (RS) prognostic and predictive value with regards to chemotherapy (CHT) application benefit has been broadly validated. In older patients its value has not been deeply addressed. This study aimed to evaluate the benefits of RS testing and to look at differences in treatment allocation for these patients when compared with younger ones. METHODS: We included data from consecutive patients with early luminal HER2-negative breast cancer, treated between 2010 and 2022 at the University Hospital Basel and Cantonal Hospital Baselland, Switzerland. The older cohort included 63 (19%) patients aged ≥70, and the younger cohort 263 (81%) patients aged <70. RESULTS: Older breast cancer patients had more co-morbidities (N = 36, 57% vs. N = 92, 35%, p = 0.002) and a higher clinical risk status (N = 49, 78% vs. N = 155, 59%; p = 0.01) when compared to younger patients. Histopathologic characteristics were significantly different between the two cohorts. Although older patients had a higher clinical risk status (78% vs. 59%) (p = 0.01), most of them (74%) received no CHT. Specifically, adjuvant CHT was administered less frequently in older than in younger patients (13% vs. 22%; p = 0.01). Moreover, older patients were less likely to complete CHT (>4 cycles: 78% vs. 97%). CONCLUSION: Breast cancer patients aged ≥70 have higher clinical risk status, more co-morbidities, higher clinical stage (driven by larger tumor size), and more often RS ≥26. However, they receive fewer adjuvant RT and CHT than those aged <70. RS maintains its independent prognostic value in older patients. However, assessing the predictive value of additional CHT benefit remains challenging due to significant differences in CHT administration. Although therapy decision-making in older patients with breast cancer still follows RS-based guidelines, clinical practice indicates an individualized treatment approach.

A phase II trial (AGO 2.11) in platinum-resistant ovarian cancer: a randomized multicenter trial with sunitinib (SU11248) to evaluate dosage, schedule, tolerability, toxicity and effectiveness of a multitargeted receptor tyrosine kinase inhibitor monotherapy.

BACKGROUND: Recurrent platinum-resistant ovarian cancer usually has a poor outcome with conventional chemotherapeutic therapy and new treatment modalities are warranted. This phase II study was conducted to evaluate sunitinib, an oral antiangiogenic multitargeted tyrosin kinase inhibitor, in this setting. MATERIAL AND METHODS: The primary end point of this randomized phase II trial was the objective response rate according to RECIST criteria and/or Gynecologic Cancer InterGroup CA125 response criteria to sunitinib in patients with recurrent platinum-resistant ovarian cancer who were pretreated with up to three chemotherapies. A selection design was employed to compare two schedules of sunitinib (arm 1: 50 mg sunitinib daily orally for 28 days followed by 14 days off drug; and arm 2: 37.5 mg sunitinib administered daily continuously). RESULTS: Of 73 patients enrolled, 36 patients were randomly allocated to the noncontinuous treatment arm (arm 1) and 37 patients were randomly allocated to the continuous treatment arm (arm 2). The mean age was 58.8 and 58.5 years, respectively. We observed six responders (complete response + partial response) in arm 1 (16.7%) and 2 responders in arm 2 (5.4%). The median progression-free survival (arm 1: 4.8 [2.9-8.1] months; arm 2: 2.9 [2.9-5.1] months) and the median overall survival (arm 1: 13.6 [7.0-23.2] months; arm 2: 13.7 [8.4-25.6] months) revealed no significant difference. Adverse events included fatigue as well as cardiovascular, gastrointestinal and abdominal symptoms, hematologic and hepatic laboratory abnormalities. Pattern and frequency of adverse events revealed no substantial differences between both treatment groups. CONCLUSIONS: Sunitinib treatment is feasible and moderately active in relapsed platinum-resistant ovarian cancer. The noncontinuous treatment schedule should be chosen for further studies in ovarian cancer.

PREPARE trial: a randomized phase III trial comparing preoperative, dose-dense, dose-intensified chemotherapy with epirubicin, paclitaxel and CMF versus a standard-dosed epirubicin/cyclophosphamide followed by paclitaxel ± darbepoetin alfa in primary breast cancer--results at the time of surgery.

BACKGROUND: Preoperative chemotherapy is a recommended treatment of both primary operable and locally advanced breast cancer. Strategies to improve efficacy include the use of anthracyclines, taxanes, and intensified dose with bone marrow support. PATIENTS AND METHODS: Patients received neoadjuvant epirubicin 90 mg/m(2) plus cyclophosphamide 600 mg/m(2) followed by paclitaxel 175 mg/m(2) (EC→T), each 3-weekly for four cycles (n = 370), or epirubicin 150 mg/m(2) followed by paclitaxel 225 mg/m(2) with pegfilgrastim followed by CMF (cyclophosphamide 500 mg/m(2), methotrexate 40 mg/m(2), fluorouracil 600 mg/m(2)) on days 1 and 8 (E(dd)→T(dd)→CMF), each 2-weekly and for three cycles (n = 363). Patients were randomly allocated to either simultaneous darbepoetin alfa (DA) (n = 356) or none (n = 377). RESULTS: Pathological complete response (pCR) rate (breast) was higher with E(dd)→T(dd)→CMF, 18.7% versus 13.2% with EC→T; P = 0.043, ypT0/Tis; ypN0 was reported in 20.9% versus 14.3% respectively; P = 0.019. Patients with grade 3 tumors and negative hormone receptor status had a significantly higher pCR rate. Mean hemoglobin values maintained higher with DA (13.6 versus 12.6 g/dl). E(dd)→T(dd)→CMF regimen showed more grade 3-4 mucositis, sensory neuropathy, and neurological complaints. Thromboembolic events were more frequent on DA (3% versus 6%; P = 0.055). CONCLUSION: Dose-dense and -intensified neoadjuvant chemotherapy with E(dd)→T(dd)→CMF was potentially superior to EC→T in terms of pCR. Primary use of DA did not affect pCR.

PREPARE trial: a randomized phase III trial comparing preoperative, dose-dense, dose-intensified chemotherapy with epirubicin, paclitaxel, and CMF versus a standard-dosed epirubicin-cyclophosphamide followed by paclitaxel with or without darbepoetin alfa in primary breast cancer--outcome on prognosis.

BACKGROUND: The objective of this study was to compare the effect of dose-intensified neoadjuvant chemotherapy with that of standard epirubicin plus cyclophosphamide followed by paclitaxel in combination with or without darbepoetin on survival in primary breast cancer. PATIENTS AND METHODS: A total of 733 patients received either four cycles of neoadjuvant epirubicin 90 mg/m(2) plus cyclophosphamide 600 mg/m(2) every 3 weeks followed by four cycles of paclitaxel 175 mg/m(2) every 3 weeks (EC→T), or three cycles of epirubicin 150 mg/m(2) every 2 weeks followed by three cycles of paclitaxel 225 mg/m(2) every 2 weeks followed by three cycles of combination chemotherapy with cyclophosphamide, methotrexate, and fluorouracil (E(dd)→T(dd)→CMF). The patients were randomly assigned to receive darbepoetin or none. The primary objective was to demonstrate a superior disease-free survival (DFS) of E(dd)→T(dd)→CMF compared with EC→T. RESULTS: Estimated 3-year DFS was 75.8% with EC→T versus 78.8% with E(dd)→T(dd)→CMF [hazard ratio (HR) 1.14; P = 0.37] and overall survival (OS) 88.4% versus 91.5% (HR 1.26; P = 0.237). Three-year DFS was 74.3% with darbepoetin versus 80.0% without (HR 1.31; P = 0.061) and OS 88.0% versus 91.8% (HR 1.33; P = 0.139). Patients with a pathologically documented complete response [pathological complete response (pCR)] had a significantly better DFS compared with those without achieving a pCR (estimated 3-year DFS: 89.2% versus 74.9%; HR 2.27; P = 0.001). CONCLUSION: Neoadjuvant dose-intensified chemotherapy compared with standard chemotherapy did not improve DFS, whereas the addition of darbepoetin might have detrimental effects on DFS.

High estrogen receptor expression in early breast cancer: chemotherapy needed to improve RFS?

One of the most controversial questions in early breast cancer treatment is the need of chemotherapy in patients with estrogen receptor positive disease. Therefore, we analyzed a group of patients with high estrogen receptor (ER) expression to scrutinize the role of chemotherapy in this situation. To gauge the effect of chemotherapy on recurrence free survival (RFS) three treatment modalities were compared: endocrine treatment only, chemoendocrine treatment, and chemotherapy. 3,971 breast cancer patients whose treatment modalities as well as ER level were known, were included in this retrospective analysis. Their level of ER expression was documented as immunoreactive score (IRS). A high ER group was defined as ER IRS ≥ 9; primary endpoint was RFS. RFS was associated with ER, with the best outcome for strong and the worst result for negative expression. Adjusted to Nottingham prognostic index (NPI), RFS did not differ between the treatment cohorts of endocrine treatment and chemoendocrine treatment (P = 0.828) in the high ER group. Patients with chemotherapy alone fared significantly worse (P = 0.003). Even in high risk patients (according to NPI) the chemoendocrine and the endocrine treatment only groups did not differ significantly (HR = 1.15; 95% CI (0.56-2.34), P = 0.709). Omission of endocrine treatment led to significantly worse outcome (P = 0.013). In conclusion, RFS was significantly longer in patients with high ER expression than with weak or no ER expression. In the high expression group, there was no significant difference in RFS between endocrine treatment only and chemoendocrine therapy-even in high risk patients, for whom chemoendocrine treatment is routinely indicated. It seems insufficient for high ER patients to only consider tumor size, nodal status, and grading in order to decide which patient will benefit from adding chemotherapy to endocrine treatment.

Intraperitoneal treatment with the trifunctional bispecific antibody Catumaxomab in patients with platinum-resistant epithelial ovarian cancer: a phase IIa study of the AGO Study Group.

OBJECTIVE: The aim of this study was to select the best catumaxomab regimen for further investigation in ovarian cancer based on confirmed tumour response. METHODS: Randomised open-label phase IIa study in women with platinum-resistant or -refractory epithelial ovarian cancer. Catumaxomab (6-hour intraperitoneal infusion on days 0, 3, 7 and 10) was administered at a low (10, 10, 10 and 10 µg) or high dose (10, 20, 50 and 100 µg). Responders were patients with either a complete (CR) or partial (PR) response. RESULTS: Forty-five patients were randomised to receive either low dose (23) or high dose (22). There were no responders in the low-dose versus one patient (5%) in the high-dose group with a PR. In the low-dose group, two patients (9%) had stable disease compared with five patients (23%) in the high-dose group. Catumaxomab was well tolerated and there was no difference between the dose groups in the incidence of treatment-induced adverse events, the most common of which were gastrointestinal and injection-site reactions. CONCLUSION: Catumaxomab had modest activity in platinum-resistant ovarian cancer. The high-dose regimen was associated with a slightly better therapeutic index than the low dose regimen.

Standard treatment of female patients with breast cancer decreases substantially for women aged 70 years and older: a German clinical cohort study.

BACKGROUND: Standard treatment of patients with breast cancer decreases with age and older persons are mostly excluded from clinical trials. We hypothesized that non-adherence to treatment guidelines occurs for women aged > or =70 years and changes overall survival (OAS) and disease-free survival (DFS). PATIENTS AND METHODS: We enrolled 1922 women aged > or =50 years with histologically confirmed invasive breast cancer treated at the University of Ulm from 1992 to 2005. Adherence to guidelines and effects on OAS and DFS for women aged > or =70 years was compared with that for younger women (50-69 years). RESULTS: Women >70 years less often received recommended breast-conserving therapy (70-79 years: 74%-83%; >79 years: 54%) than women aged < or =69 years (93%). Non-adherence to the guidelines on radiotherapy (<70 years: 9%; 70-79 years: 14%-27%; >79 years: 60%) and chemotherapy (<70 years: 33%; 70-79 years: 54%-77%; > 79 years: 98%) increased with age. Omission of radiotherapy significantly decreased OAS [< or =69 years: hazard ratio (HR) = 3.29; P <0.0001; > or =70 years: HR = 1.89; P = 0.0005] and DFS (< or =69 years: HR = 3.45; P <0.0001; > or =70 years: HR = 2.14; P <0.0001). OAS and DFS did not differ significantly for adherence to surgery, chemotherapy, or endocrine therapy. CONCLUSION: Our study confirms that substandard treatment increases considerably with age. Omission of radiotherapy had the greatest impact on OAS and DFS in the elderly population.

Color Doppler ultrasound and computed tomographic angiography for perforator mapping in DIEP flap breast reconstruction revisited: A cohort study.

INTRODUCTION: Preoperative imaging by Computed Tomographic Angiography (CTA) has been promoted a gold standard tool for perforator mapping in abdominally based microsurgical breast reconstruction, while Color Doppler Ultrasound (CDU) has lost its popularity. As the CTA X-ray exposure might have long-term consequences for patients, CDU has regained importance for preoperative workup in our center. Our aim was to revisit the role of CDU by comparing the reliability of CDU and CTA in predicting intraoperative perforator selection. MATERIALS AND METHODS: We performed a retrospective chart review study of patients who underwent microsurgical breast reconstructions with DIEP flaps at our institution. Both CTA and CDU were performed prior to the surgery, and both imaging entities were thoroughly examined by the surgical team. Perforator identification, number, size, and location were assessed and correlated with CTA and CDU data and with intraoperative findings. RESULTS: We identified 98 patients who received 125 DIEP flap surgeries. A significantly stronger correlation was found between CDU and intraoperative findings of perforator detection and size (p<0.0001) and selection (r = 0.9987, CI 0.9981-0.9991, p < 0.0001 and r = 0.01, CI -0.18-0.2, p = 0.91, respectively), when compared with CTA data. If none of the preoperative imaging studies matched intraoperative perforator selection, an association with a higher incidence of flap loss (Odds ratio 4.483, CI 0.5068-39.65, p = 0.2171) was found. CONCLUSIONS: Our data suggests that CDU might regain relevance as a safe and reliable preoperative imaging study, without the risk and potential consequences of X-ray exposure. Preoperative imaging tools like CDU and CTA should be considered part of the gold standard in abdominally based free flap breast reconstruction.

Statement by the Kommission Ovar of the AGO: The New FIGO and WHO Classifications of Ovarian, Fallopian Tube and Primary Peritoneal Cancer.

More than 25 years after the last revision, in 2012 the FIGO Oncology Committee began revising the FIGO classification for staging ovarian, Fallopian tube and primary peritoneal cancers. The new classification has become effective with its publication at the beginning of 2014. Following recent findings on the pathogenesis of ovarian, Fallopian tube and primary peritoneal cancer and reflecting standard clinical practice, the three entities have now been classified uniformly. The histological subtype is included (high-grade serous - HGSC; low-grade serous - LGSC; mucinous - MC; clear cell - CCC; endometrioid - EC). Stages III and IV have been fundamentally changed: stage IIIA now refers to a localized tumor limited to the pelvis with (only) retroperitoneal lymph node metastasis (formerly classified as IIIC). Stage IV has been divided into IVA and IVB, with IVA defined as malignant pleural effusion and IVB as parenchymatous or extra-abdominal metastasis including inguinal and mediastinal lymph node metastasis as well as umbilical metastasis. A new WHO classification was published almost concurrently. The classification of serous tumors addresses the issue of the tubal carcinogenesis of serous ovarian cancer, even if no tubal precursor lesions are found for up to 30 % of serous high-grade cancers. The number of subgroups was reduced and subgroups now include only high-grade serous, low-grade serous, mucinous, seromucinous, endometrioid, clear cell and Brenner tumors. The category "transitional cell carcinomas" has been dropped and the classification "seromucinous tumors" has been newly added. More attention has been focused on the role of borderline tumors as a stage in the progression from benign to invasive lesions.

Participation in adjuvant clinical breast cancer trials: does study participation improve survival compared to guideline adherent adjuvant treatment? A retrospective multi-centre cohort study of 9,433 patients.

UNLABELLED: Adjuvant clinical trials (CTs) usually compare a standard treatment regime versus an innovative new substance or regimen. Participation in CT however, is available for only few patients and exclusion criteria are usually very strict. Therefore we used an unselected patient cohort to investigate the following questions: MATERIAL AND METHODS: This German retrospective multi-centre cohort study included 9433 patients with primary breast cancer recruited from 1992 to 2008. RESULTS: One thousand two hundred and fifty-five (13.3%) patients participated in adjuvant clinical trials (PA) and 8178 (86.7%) did not (NPA). RFS was higher among participants (PA) than among non-participants (NPA) [p=0.006], but differences in overall survival (OAS) were not significant [p=0.15]. When stratified for guideline adherence, the outcome was not different for guideline conform NPA [RFS: p=0.88] [OAS: p=0.37] compared to PA. Survival parameters however, were significantly poorer in non-guideline conform PA [RFS: p<0.001] [OAS: p<0.001] and non-guideline conform NPA [RFS: p<0.001] [OAS: p<0.001] as compared to guideline adherent PA. DISCUSSION: There is a strong association between guideline adherence in adjuvant treatment in BC and survival. PA in clinical trials tended to higher survival rates, but only if guideline-adherent treatment was applied. Patients who do not have access to clinical trials may profit substantially from guideline-adherent adjuvant treatment.

Infectious Epstein-Barr virus lacking major glycoprotein BLLF1 (gp350/220) demonstrates the existence of additional viral ligands.

The binding of the viral major glycoprotein BLLF1 (gp350/220) to the CD21 cellular receptor is thought to play an essential role during infection of B lymphocytes by the Epstein-Barr virus (EBV). However, since CD21-negative cells have been reported to be infectible with EBV, additional interactions between viral and cellular molecules seem to be probable. Based on a recombinant genomic EBV plasmid, we deleted the gene that encodes the viral glycoprotein BLLF1. We tested the ability of the viral mutant to infect different lymphoid and epithelial cell lines. Primary human B cells, lymphoid cell lines, and nearly all of the epithelial cell lines that are susceptible to wild-type EBV infection could also be successfully infected with the viral mutant in vitro, although the efficiency of infection with BLLF1-negative virus was clearly lower than the one observed with wild-type EBV. Our studies show that the interaction between BLLF1 and CD21 is not absolutely required for the infection of lymphocytes and epithelial cells, indicating that viral molecules other than BLLF1 can mediate the binding of EBV to its target cells. In this context, our results further suggest the hypothesis that additional cellular molecules, apart from CD21, allow virus entry into these cells.