Oncology-Pathology Working Group

OPWG - Connecting Veterinary Oncologists and Pathologists

Putting Veterinary Cancer Care on the Right Path

The overall mission of the group is to foster and promote an integrated working relationship between veterinary oncologists (medical, surgical and radiation) and pathologists (anatomic and clinical) to facilitate and ensure the highest standard of pathology support and reporting for the advancement of veterinary clinical oncology and cancer research.

Through this interdisciplinary effort, the group will, amongst other efforts, work to establish consensus documents designed to standardize aspects of and provide guidelines for oncologic pathology. The group will additionally seek sponsorship and support for said documents from other groups/organizations with similar interests including but not limited to the: American College of Veterinary Internal Medicine (Oncology), Veterinary Cooperative Oncology Group, Veterinary Radiation Therapy Oncology Group, and Veterinary Society of Surgical Oncology.


Mark your calendar. The next OPWG meeting will be held virtually this fall. Stay tuned for details.

The VCS OPWG was initially established within VCS in 2011 thereafter becoming a joint initiative of both the Veterinary Cancer Society and the American College of Veterinary Pathologists in 2013. The interest and support by the ACVP in the mission and goals of the, now, VCS-ACVP OPWG is a testament to the interdisciplinary nature of this initiative! The OPWG works with and consists of members affiliated with both VCS and ACVP as we continue to work collectively across disciplines toward standardization and provision of guidelines in veterinary oncologic pathology.

Become a member

If you are interested in working with and becoming a member of the OPWG, please complete the OPWG Membership Application Form by clicking on the “Become An OPWG Member” link and submit to

Active membership in VCS, ACVP or other international equivalent (e.g. ESVONC, ECVP) is required for OPWG membership eligibility. Active membership in AAVLD or ASVCP also meets OPWG membership eligibility for current residents.

Joanne Intile

Specific objectives of the group include:

  • To facilitate and promote a working relationship and communication between veterinary oncologists (surgical, medical, and radiation) and pathologists (anatomic & clinical)
  • To establish consensus and promote species-specific tumor grading systems, prognostic parameters, and predictive parameters based upon published peer-reviewed scientifically-supported evidence
  • To identify deficient or inadequate areas in oncology/pathology in need of further investigation
  • To provide recommendations/guidelines on research-related (retrospective & prospective studies) pathological evaluation and design to strengthen published scientific data
  • To facilitate investigative collaborations between oncologists and pathologists
  • To promote education and outreach to general practitioners and trainees
  • To promote increased interdisciplinary training during residency
  • To promote education & training in oncologic pathology and, ultimately, to put forth criteria and goals for a one-year fellowship for advanced specialized training in oncologic pathology

To function as a resource to disseminate and provide accessible information on but not limited to:

  • Tumor biopsy techniques
  • Tumor biopsy sample submission
  • Tissue trimming methods for surgical margin evaluation
  • Recommended tumor biopsy reporting parameters
  • Post-report options available to clinicians
  • Use and interpretation of histochemical and immunohistochemical stains
  • Consensus on species-specific tumor grading schemes
  • Consensus on species-specific tumor prognostic parameters
  • Consensus on species-specific tumor predictive parameters
  • Specific areas in need of further investigation


Joanne Intile

Joanne Intile DVM, MS, DACVIM (Oncology)

Samantha Schlemmer

Samantha Schlemmer DVM, MS, DACVP (CP)

Jennifer Hofer DVM, DACVIM (Oncology)

Heather Priest

Past President
Heather Priest DVM, DACVP (CP)

Deb Kamstock

Founding President
Debra Kamstock DVM, PhD, DACVP (AP)

Canine Lymphoma Subgroup

Chair: Michael Childress, DVM MS DACVIM (Oncology)

Co-Chair: Luca Aresu, DVM, PhD

Focus: To create evidence-based, relevant and practical, best-practice guidelines for the diagnosis and classification of canine nodal lymphoma.

Canine Mammary Tumor Subgroup

Chair: Henrik Ronnberg, DVM PhD DECVIM-CA (Oncology)

Co-Chair: Laura Pena, DVM PhD DECVP (AP)

Focus: Classification and grading of malignant canine mammary tumors

Canine Prostate Tumor Subgroup

Chair: Chiara Palmieri, DVM, PhD DECVP (AP)

Co-Chair: William TN Culp, VMD DACVS

Focus: Histopathologic classification of canine prostate cancer

Clinical Pathology Subgroup

Chair: Heather Priest, DVM DACVP (CP)

Co-Chair: Cecilia Robat, DVM DACVIM (Oncology)

Focus: Diagnostic immunocytochemistry: applications and markers

Education and Outreach

Chair: Jennifer Steinberg, DVM MS Dipl. ACVP (CP)

Co-Chair: Rachel Venable, DVM MS DACVIM (Oncology)

Focus: Oncology and pathology residency cross-training: past, present, future

MCT Subgroup, Prognostic & Predictive Markers

Chair: Doug Thamm, DVM MS DACVIM (Oncology)

Co-Chair: Josh Webster, DVM PhD DACVP (AP)

Focus: Prognostic and predictive significance of KIT expression and c-kit
mutations in canine cutaneous mast cell tumors

MCT Subgroup, Update on Grading

Chair: Davide Berlato, DECVIM-CA (Onc) MSc (Clinical Onc) PhD MRCVS

Co-Chair: Roberta Rassoto, DVM PhD MRCVS DECVP (AP)

Focus: Update to the current OPWG CCMCT consensus on grading (est. Feb 2013)

Canine Melanoma Subgroup

Chair: Philip Bergman, DVM PhD DACVIM (Oncology)

Co-Chair: Rebecca Smedley, DVM MS DACVP (AP)

Focus: Prognostic markers for canine melanocytic tumors

Soft Tissue Sarcoma Subgroup

Chair: Marlene Hauck, DVM PhD DACVIM (Oncology)

Co-Chair: Donald Meuten, DVM PhD DACVP (AP & CP)

Focus: Grading of canine soft tissue sarcomas

Relevant Links
  • To access the OPWG Members Online Discussion Forum, click here.
  • Access to the consensus paper Recommended guidelines for submission, trimming, margin evaluation, and reporting of tumor biopsy specimens in veterinary surgical pathology. (Vet Pathol. 2011 Jan;48(1):19-31) is available at Vet SXBX Guidelines.
  • OPWG Resident Cross-Training Survey Results
Kim Freeman

Frequently Asked Questions

The Oncology-Pathology Working Group (OPWG) was established in 2011 as an initiative within the Veterinary Cancer Society to foster and promote an integrated working relationship between veterinary oncologists (medical, surgical, & radiation) and pathologists (anatomic and clinical) to facilitate and ensure the highest standard of pathology support and reporting for the advancement of veterinary clinical oncology and cancer research. In 2013, the American College of Veterinary Pathologists (ACVP) expressed interest in the mission of the OPWG, after which the initiative became a joint venture of VCS and ACVP as it stands today.

Anyone interested in veterinary oncology and pathology is welcome to join the OPWG, including board-certified and board-eligible specialists, veterinary residents, interns, students, technicians and researchers (PhDs, PhD students, etc); however, active membership in ACVP, VCS, ECVP, ESVONC or other international equivalent is required. Membership in AAVLD or ASVCP is also recognized for membership eligibility for residents in training. Membership type and voting eligibility is determined by members’ credentials. Detailed information regarding membership type is provided at the bottom of these FAQs.

If you are interested in becoming a member of the OPWG, please download and complete the OPWG Membership Application Form and submit to Active membership in VCS, ACVP, ESVONC, ECVP or other international equivalent is required for OPWG membership eligibility. Your application will be reviewed and you will be contacted with additional information.

No dues are owed directly to the OPWG for membership; however, dues associated with membership in either the Veterinary Cancer Society (VCS), American College of Veterinary Pathologists (ACVP), European Society of Veterinary Oncology (ESVONC), European College of Veterinary Pathology (ECVP) or other international equivalent are indirectly required as active membership in one of these organizations is required to be eligible for membership of the OPWG.

The annual OPWG is held virtually in the fall, typically between the annual VCS and ACVP conferences. Specific information regarding the location, date, and time of the annual OPWG meeting is distributed to the membership prior to the meeting.

Since COVID, the annual OPWG meeting has also been held virtually in conjunction with or at a time between the annual VCS and ACVP meetings. Keep an eye on the “Updates” section of this webpage for annual meeting information and, for members, on your emails as the annual meetings approach.

If you’re interested in actively participating in a specific OPWG subgroup, you can contact the subgroup Chair directly (as listed on the OPWG website), or send an email to indicating your interest. It will be forwarded to the appropriate individual.

Subgroups must consist of a minimum of 6 members, including the Chair and CoChair, and no more than 20 members (although the maximum number may vary with Executive Council approval depending on the circumstances and goals of the Subgroup). Subgroups are composed of as even a distribution as possible of pathologists and oncologists. The Chair and Co-Chair positions are always held by one oncologist and one pathologist.

The OPWG Subgroups are the core of the OPWG with regard to establishing consensus documents and/or reviews on any number of various oncologic pathology topics including but not limited to species and tumor-specific grading schemes, prognostic markers, predictive markers, biologically relevant surgical margins, and relevant immunohistochemical markers; diagnostic, prognostic, and predictive. These consensus documents are established via diligent and critical review by all subgroup members of respective and relevant peer-reviewed literature followed by, at times, heated debates and rewarding discussion until consensus is reached.

Subgroup members work with the Subgroup Chair and Co-Chair as well as all other members of the given subgroup. Together, the group identifies relevant literature relative to the particular focus of the group. A literature review form, to provide guidelines and maintain consistency between reviews, is provided to all members. Each member diligently, critically, and independently reviews the selected literature, while completing a review form for each of the respective papers. The Chair and Co-Chair collate and review all of the members’ reviews and produce a single initial consensus document. This document is then reviewed, discussed, and modified by the group as a whole until consensus is reached.

Once a subgroup’s consensus document is submitted to the OPWG, it is posted on the OPWG online forum site for all OPWG members to review and comment on. Following discussions by the OPWG membership (in conjunction with comments from the subgroup members themselves), the consensus document will be voted on by voting members for overall consensus by the OPWG. Once general consensus by the OPWG is established, the document may be circulated amongst other groups (i.e. ACVP, ACVIM Oncology, VCOG, VRTOG, VSSO) for further support (or lack thereof).

Yes, once a consensus document reaches completion (defined as approval by the OPWG general membership and review with support or not by additional organizations and working bodies as mentioned above), documents will be submitted for publication into appropriate peer-reviewed journals. Primary and senior authors will reflect that of the Subgroup Chair and Co-Chair with additional authors consisting of the subgroup members.

There are four membership categories: Full, Associate, Affiliate, and Honorary. Members from all categories are encouraged to participate in the OPWG via the online discussion boards, individual subgroups, and attending annual meetings. Voting eligibility and holding office as an executive officer or subgroup chair, however, is reserved for full members.

A Full Member is a board certified veterinary oncologist, pathologist, radiation oncologist, or surgeon (oncology fellow) as recognized by the American Veterinary Medical Association (AVMA), European Board of Veterinary Specialization (EBVS) or other international equivalent.

An Associate Member is a board certified veterinarian (i.e. DVM or other international equivalent) who has completed or is in the process of completing a 3-year residency in oncology, pathology, or radiation oncology, or is in the process of completing a surgical oncology fellowship, as recognized by the American Veterinary Medical Association (AVMA), European Board of Veterinary Specialization (EBVS),or other international equivalent.

An Affiliate Member is a board certified veterinary specialist in a discipline other than oncology, pathology, or radiation oncology, to include board certified surgeons who have not completed a surgical oncology fellowship, or is a board certified veterinarian (DVM, VMD, or other international equivalent), veterinary technician/nurse, professional veterinary medical student, or graduate student who meet the general VCS OPWG membership requirements.

An Honorary Member is an individual who has, through their career, whether veterinary or human, demonstrated a special interest in and excelled in the area of oncologic pathology especially with a goal of standardization and improved reporting for the benefit of diagnostic oncologic pathology and cancer research.

Special modifications regarding membership category can be made by the Executive Committee upon review and approval of a proposal submitted by the respective member requesting membership modification.

Additional details of membership, including maintenance requirements of membership, are available in Section V of the OPWG Constitution which can be accessed via the OPWG online forum site.

The OPWG coolness factor is from the overwhelming energy, drive, and passion by all the amazing individuals who believed in and still believe in the mission and potential of the OWPG!

Contact Us

  • For general information or inquiries please contact
  • For more specific inquires or if interested in chairing or co-chairing a subgroup, please contact us at
  • If you are interested in actively working on one of the subgroups listed above, please email and provide the name of the subgroup you are interested in working with.

Please check back to the OPWG web page intermittently as updates will continuously be made.