Difference between revisions of "Breast cancer grading"

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#*Minimal <10% = 3.
#*Minimal <10% = 3.
# Mitotic rate.
# Mitotic rate.
#*0-5 mitosis/10 [[HPF]] (1.52 mm^2 --or-- 0.0152 mm^2 * 10) = 1.
#*0-5 mitosis/10 [[HPF]] (1.52 mm<sup>2</sup> --or-- 0.0152 mm<sup>2</sup> * 10) = 1.
#*6-10 mitosis/10 HPF (1.52 mm^2) = 2.
#*6-10 mitosis/10 HPF (1.52 mm<sup>2</sup>) = 2.
#*>11 mitosis/10 HPF (1.52 mm^2) = 3.
#*>11 mitosis/10 HPF (1.52 mm<sup>2</sup>) = 3.
Mnemonic: ''TMN'' = tubule formation, mitotic rate, nuclear grade.
Mnemonic: ''TMN'' = tubule formation, mitotic rate, nuclear grade.


Revision as of 22:48, 10 March 2016

Breast cancer grading is useful prognosticator. It is done routinely on all invasive breast cancers.

The most common is the Nottingham system, also known as Scarff-Bloom-Richardson.

Nottingham system

Nottingham is based on:

  1. Nuclear grade.
    • Small, regular (1.5-2x RBC dia.) = 1.
    • Moderated variability = 2.
    • Marked variation (>2.5x RBC dia.) = 3.
  2. Tubule formation.
    • Majority of tumour - tubules >75% = 1.
    • Moderate - 10% to 75% = 2.
    • Minimal <10% = 3.
  3. Mitotic rate.
    • 0-5 mitosis/10 HPF (1.52 mm2 --or-- 0.0152 mm2 * 10) = 1.
    • 6-10 mitosis/10 HPF (1.52 mm2) = 2.
    • >11 mitosis/10 HPF (1.52 mm2) = 3.

Mnemonic: TMN = tubule formation, mitotic rate, nuclear grade.

Notes:

  • Elston & Ellis devised the system that is used.[1] They also wrote a follow-up article in 2002.[2]

Note about mitosis counting

  • One really ought to adjust for the size of the field of view.
  • Most of modern microscopes have an eye piece diameter of 22 mm. Therefore, the field diameter at 40x is approximately 22 mm / 40x ~= 0.55 mm and the field of view is pi/4*(0.55 mm)2 = 0.2376 mm2.
    • Thus, on a typical modern microscope (with a FOV of 0.2376 mm2) one should sample 6 or 7 fields of view (FsOV).
      • Calculation: 1.52 mm2 (sampling area) / 0.2376 mm2 (area / FOV ) = 6.40 FsOV.
  • RANT: Sampling 10 fields, where the field of view (FOV) is 0.152 mm2, is not the same as sampling ten fields, where the FOV is 0.312 mm2. It surpring that Elston & Ellis ignore the fact that "10 HPFs" on different microscopes represent different sample areas and that they do not standardize the sampling area.

Calculating Nottingham score

  • Grade I = 3-5 points.
  • Grade II = 6-7 points.
  • Grade III = 8-9 points.

Notes:

  • Most tumours are grade II.
  • The mitotic score is most often 1/3.
  • The nuclear score is rarely 1/3 -- even in the tubular subtype.[3]

See also

References

  1. ↑ Elston CW, Ellis IO (September 2002). "Pathological prognostic factors in breast cancer. I. The value of histological grade in breast cancer: experience from a large study with long-term follow-up. C. W. Elston & I. O. Ellis. Histopathology 1991; 19; 403-410". Histopathology 41 (3A): 151–2, discussion 152–3. PMID 12405945.
  2. ↑ Elston CW, Ellis IO (November 1991). "Pathological prognostic factors in breast cancer. I. The value of histological grade in breast cancer: experience from a large study with long-term follow-up". Histopathology 19 (5): 403–10. PMID 1757079.
  3. ↑ MUA. 20 January 2009.
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