De novo and recurrent metastatic breast cancer - A systematic review of population-level changes in survival since 1995.

BACKGROUND: Advances in breast cancer (BC) care have reduced mortality, but their impact on survival once diagnosed with metastasis is less well described. This systematic review aimed to describe population-level survival since 1995 for de novo metastatic BC (dnMBC) and recurrent MBC (rMBC). METHODS: We searched MEDLINE 01/01/1995-12/04/2021 to identify population-based cohort studies of MBC reporting overall (OS) or BC-specific survival (BCSS) over time. We appraised risk-of-bias and summarised survival descriptively for MBC diagnoses in 5-year periods from 1995 until 2014; and for age, hormone receptor and HER2 subgroups. FINDINGS: We identified 20 eligible studies (14 dnMBC, 1 rMBC, 5 combined). Potential sources of bias in these studies were confounding and shorter follow-up for the latest diagnosis period.For dnMBC, 13 of 14 studies reported improved OS or BCSS since 1995. In 2005-2009, the median OS was 26 months (range 24-30), a median gain of 6 months since 1995-1999 (range 0-9, 4 studies). Median 5-year OS was 23% in 2005-2009, a median gain of 7% since 1995-1999 (range -2 to 14%, 4 studies). For women ≥70 years, the median and 5-year OS was unchanged (1 study) with no to modest difference in relative survival (range: -1·9% (p = 0.71) to +2·1% (p = 0.045), 3 studies). For rMBC, one study reported no change in survival between 1998 and 2006 and 2007-2013 (median OS 23 months). For combined MBC, 76-89% had rMBC. Three of four studies observed no change in median OS after 2000. Of these, one study reported median OS improved for women ≤60 years (1995-1999 19·1; 2000-2004 22·3 months) but not >60 years (12·7, 11·6 months). INTERPRETATION: Population-level improvements in OS for dnMBC have not been consistently observed in rMBC cohorts nor older women. These findings have implications for counselling patients about prognosis, planning cancer services and trial stratification. FUNDING: SL was funded in part by a National Health and Medical Research Council (NHMRC) Project Grant ID: 1125433. NH was funded by the NBCF Chair in Breast Cancer Prevention grant (EC-21-001) and a NHMRC Investigator (Leader) grant (194410). BD and SAP were funded in part by the NHMRC Centre of Research Excellence in Medicines Intelligence (1196900).

4Pi-confocal microscopy of live cells.

By coherently adding the spherical wavefronts of two opposing lenses, two-photon excitation 4Pi-confocal fluorescence microscopy has achieved three-dimensional imaging with an axial resolution 3-7 times better than confocal microscopy. So far this improvement was possible only in glycerol-mounted, fixed cells. Here we report 4Pi-confocal microscopy of watery objects and its application to the imaging of live cells. Water immersion of 4Pi-confocal microscopy of membrane stained live Escherichia coli bacteria attains a 4.3-fold better axial resolution as compared to the best water immersion confocal microscope. The resolution enhancement results into a vastly improved three-dimensional representation of the bacteria. The first images of live biological samples with an all-directional resolution in the 190-280 nm range are presented here, thus establishing a new resolution benchmark in live-cell microscopy.

Electric field depolarization in high aperture focusing with emphasis on annular apertures

Electromagnetic focusing theory of light predicts that at high apertures field components arise that are polarized perpendicular to the initial polarization. Although vectorial depolarization has received considerable attention in focusing theory, no evidence has been presented as to its relevance in experiments. We measure the intensity of the perpendicularly orientated field in the focal region by utilizing monomolecular, fluorescent polydiacetylene layers whose transition dipoles are orientated in a single direction. For a 1.4 numerical aperture oil objective lens illuminated with linearly x-polarized light, we find that the integral of the modulus squared of the y-polarized focal field amounts to 1.5% of its x-polarized counterpart. In particular, we show here that the depolarization increases when using annular apertures. Annuli formed by a central obstruction with a diameter of 89% of that of the entrance pupil raise the integral to 5.5%. This compares well with the value of 5.8% predicted by electromagnetic focusing theory; however, the depolarization is also due to imperfections connected with focusing by refraction. Besides fluorescence microscopy and single molecule spectroscopy, the measured intensity of the depolarized component in the focal plane is relevant to all forms of light spectroscopy combining strong focusing with polarization analysis.

Polarization effects in 4Pi confocal microscopy studied with water-immersion lenses.

We studied the effect of electric field orientation on the point-spread function (PSF) of a 4Pi microscope. We show that in a standard 4Pi arrangement the orientation of the field can be used for changing between constructive- and destructive-mode 4Pi microscopy. The effect is counteracted by introduction of a phase shift of pi into one of the half-arms. This compensation is compulsory during illumination with unpolarized or circularly polarized light. By performing our experiments with 1.2-N.A. water-immersion lenses, we demonstrate that water immersion is suitable for 4Pi confocal microscopy. At a two-photon excitation wavelength of 1064 nm, the water 4Pi confocal PSF features an axial lobe of 40% above and below the focal plane, which, by linear filtering, can be unambiguously removed. The measured axial full width at half-maximum of the PSF is 240 nm. This is 4.3 times narrower than its single-lens confocal counterpart. The 4Pi confocal microscope sets a new resolution benchmark in three-dimensional imaging of watery samples.

4Pi-confocal imaging in fixed biological specimens.

By combining the wavefronts produced by two high-aperture lenses, two-photon 4Pi-confocal microscopy allows three-dimensional imaging of transparent biological specimens with axial resolution in the 100-140-nm range. We reveal the imaging properties of a two-photon 4Pi-confocal microscope as applied to a fixed cell. We demonstrate that a fast, linear point deconvolution suffices to achieve axially superresolved 3D images in the cytoskeleton. Furthermore, we describe stringent algorithms for alignment and control of the two lenses. We also show how to compensate for the effects of a potential refractive index mismatch of the mounting medium with respect to the immersion system.