Unfortunately, quantitative estimation is a lost "art" because modern medicine in the early 2000s is disrespecting of anything which is subject to significant variation as to precision between observers. Basically, scientists are lazy & quick to find fault with anything which cannot quickly qualify for grant money. When one considers the poor degree of diagnostic agreement between experts (HERE) of all types and in any profession, one should not discard the value of an individual practitioner giving his or her "best shot" at quantitative estimates of abnormalities.

Stimulated originally in the 1980s by urologist, Gary Haney (to begin quantifying cancer chips in TURP specimens & metatsatic burden in positive lymph nodes), "quantitative oncopathology" is a term subsequently coined in our group by Dr. Shaw in the early 1990s to describe efforts to quantitate (especially as to tumor volume) features of tumor pathology beyond the confines of staging systems. We have also not experienced any system which attempted to estimate the amount of tumor-host-contact surface area of any tumor (less area in circumscribed tumors and hugely greater in highly invasive tumors).

Cancer in general:

• stage: We have had the constantly evolving staging systems for many decades. But who goes to the trouble to mention the quantity of involvement an any particular T or other stage? Would it make any difference in treatment decisions were such known?
• tumor burden: Who bothers to give any estimate of grams of cancer-cell-containing tumor or estimated grams thereof of actual tumor cells? Would there be any significance to 0.5 grams of tumor burden vs. 10 grams ? If 8 of 10 lymph nodes are positive, does it make any difference if the estimated metastatic tumor burden is 1 gram (1 cubic CM) vs. 8 grams? How about there being significance were that situation after neoadjuvant treatment with an impressive clinical response in a biopsy-proven, positive-node situation [L11-1205]? Hartmann's fixative can markedly help one select samples within a post-neoadjuvant silhouette in order to estimate reduction of burden of primary tumor [L11-3894].
• tumor circumscription: As noted below, does the total cancer-stromal interface surface area make any difference? Does it mean anything that a spherical cancer of any type has a very smoothly "pushing" periphery with the tumor-stromal contact interface surface area being that of a simple circle vs. a tumor of about the same size with highly spiculated & finely divided silhouette having a tumor-stromal contact interface surface area 100 times larger than the smooth spherical tumor? In conservative breast cancer surgery decision making, it is of great interest to know whether tumors are tightly configured vs. dispersed into multiple macro or micro epicenters or radiating macro or micro serpigenous peripheral extensions. But does it have significance?
• surgical margins: Is it worthwhile to know that margins only have a very microscopic, confined & focal positivity as opposed to a square centimeter or more of positivity or multifocal positivity?

• Gleason score determination asks that pathologists estimate the percentage of each cancer pattern in the overall case and, in some programs, the percentages in each cancerous biopsy core.
• Biopsy core measures: In the mid 1990s, some programs asked pathologists to measure the core length of cancerous involvement of any cancer-containing biopsy core and to approximate the core percentage of cancerous involvement of each cancerous core.
• Gland percentage: By 2009, one had begun to see prognostic comments in publications in, for example, prostate cancer: if, at radical prostatectomy, the cancer is all intraglandular and only accounts for 10% or less of the gland, the odds against recurrent cancer are excellent. Yet, in 2010, even at JHU, it was surprising to have a friend undergo that surgery there and the report not mention quantitative information.

Breast cancer: Is it helpful to note that the quantity of residual primary breast cancer after neoadjuvant treatment is 1/10th the quantity of the residual node mets? Does it mean anything that a case had the original node dissection containing over 100 times the metastatic volume than the primary volume? Does the amount of invasion in a large cloud of CIS (as in a Tabar Tumor) make any difference [L04-3026]? Is it of intuitive interest that the post-neoadjuvant treatment mammographic silhouette is 3.2 CM but that there is scant residual tumor, estimated at about 3 cubic millimeters? Does the number of positive nodes indicate risk of local recurrence or the percentage of nodes removed which are positive add more risk detail? Does the quantity of tumor cellularity in nodes matter?

Colon cancer: Intramucosal invasion is CIS (Tis). Is futher surgery always indicated in older patients if the cancer is small & thin and intramucosal and at some distance from a clear polyp stalk margin ( a low Haggitt level) if the cancer is grade I/II and negative for high risk histological features [S10-10767]?

Leukemia: Everyone is accustomed to considering percentages of blasts in both peripheral blood and in marrow. But what about dealing with the discordances between standard morphology & the determinations by such as flow cytometry?

Melanoma: Can it help in the decision about whether or not to perform sentinel node biopsy if the pathology report carefully notes quantitative information BEYOND Clark level and AJCC staging [L10-1448]?

Myeloma: Is there an advantage to optimal treatment decision making if the diagnosing pathologist knows (as he/she interprets the slides) something about current quantitative information as to serum tumor markers, etc? Since post-treatment persistence of "myeloma" might trigger marrow transplant, how does one deal with disparities between plasma cell count between standard morphology, IHC counts, and flow cytometry counts?

Ovarian: Especially in clinically massage pelvic mass situations, does if make any difference in advising patient/family prognostically if there is an estimate indicating that the tumor is a minor percentage of the total mass (example: 10800 g. clinical lesion becomes 880g. tissue once fluid is removed and around 50 g. is actual malignant epithelium...primary TCC of ovary [L11-3500])?

(posted 22 June 2010; latest additions 24 April 2011)